Using 5 V adapter to power 12 V cordless phone
I am trying to power a 12 V 8 W cordless phone using a 5 V 1 A wall adapter.
I am using a step up DC/DC boost converter MT3608 for boosting output from 5 V to 12 V.
Theoretically it works - when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter - it shows 12 V.
But as soon as I connect the cordless the voltage drops to 2-3 V and cordless does not power on. So its not working on load.
I also have a 7.4 V li-ion cells which powers on the cordless fine - using the boost convertor.
My question is the DC coming from adapter different than DC coming from battery?
Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Please help me understand this behavior of adapter and what's wrong in what I am trying to do?
batteries boost
edited yesterday
Jakub Rakus
2,11131121
asked yesterday
Raool
191
New contributor
Raool is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I am trying to power a 12 V 8 W cordless phone using a 5 V 1 A wall adapter.
I am using a step up DC/DC boost converter MT3608 for boosting output from 5 V to 12 V.
Theoretically it works - when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter - it shows 12 V.
But as soon as I connect the cordless the voltage drops to 2-3 V and cordless does not power on. So its not working on load.
I also have a 7.4 V li-ion cells which powers on the cordless fine - using the boost convertor.
My question is the DC coming from adapter different than DC coming from battery?
Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Please help me understand this behavior of adapter and what's wrong in what I am trying to do?
batteries boost
edited yesterday
Jakub Rakus
2,11131121
asked yesterday
Raool
191
New contributor
Raool is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
23
I don't think $5 V × 1 A> 8 W$.
– Harry Svensson
yesterday
7
A 5V 1A wall adapter cannot provide the 8 W that the phone requires, regardless of any boost converter that you are using. As a result, the adapter is limiting its output current and the voltage sags through. Please try a 2 A or higher adapter instead.
– Andrey Akhmetov
yesterday
9
Just get a 12V 1A wall wart. Readily available. Cheap. Problem solved. The only wrinkle may be matching the connector plug.
– Phil Freedenberg
yesterday
1
Craigslist: power adapter for sale. 5v 1A. ------------ craigslist: WTB power adapter. 12V, 8W.
– Harper
7 hours ago
add a comment |
I am trying to power a 12 V 8 W cordless phone using a 5 V 1 A wall adapter.
I am using a step up DC/DC boost converter MT3608 for boosting output from 5 V to 12 V.
Theoretically it works - when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter - it shows 12 V.
But as soon as I connect the cordless the voltage drops to 2-3 V and cordless does not power on. So its not working on load.
I also have a 7.4 V li-ion cells which powers on the cordless fine - using the boost convertor.
My question is the DC coming from adapter different than DC coming from battery?
Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Please help me understand this behavior of adapter and what's wrong in what I am trying to do?
batteries boost
edited yesterday
Jakub Rakus
2,11131121
asked yesterday
Raool
191
New contributor
Raool is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I am trying to power a 12 V 8 W cordless phone using a 5 V 1 A wall adapter.
I am using a step up DC/DC boost converter MT3608 for boosting output from 5 V to 12 V.
Theoretically it works - when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter - it shows 12 V.
But as soon as I connect the cordless the voltage drops to 2-3 V and cordless does not power on. So its not working on load.
I also have a 7.4 V li-ion cells which powers on the cordless fine - using the boost convertor.
My question is the DC coming from adapter different than DC coming from battery?
Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Please help me understand this behavior of adapter and what's wrong in what I am trying to do?
batteries boost
batteries boost
edited yesterday
Jakub Rakus
2,11131121
asked yesterday
Raool
191
New contributor
Raool is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited yesterday
Jakub Rakus
2,11131121
asked yesterday
Raool
191
New contributor
Raool is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited yesterday
Jakub Rakus
2,11131121
edited yesterday
Jakub Rakus
2,11131121
edited yesterday
Jakub Rakus
2,11131121
2,11131121
asked yesterday
Raool
191
New contributor
Raool is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
Raool
191
asked yesterday
Raool
191
191
New contributor
Raool is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
Raool is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
Raool is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
23
I don't think $5 V × 1 A> 8 W$.
– Harry Svensson
yesterday
7
A 5V 1A wall adapter cannot provide the 8 W that the phone requires, regardless of any boost converter that you are using. As a result, the adapter is limiting its output current and the voltage sags through. Please try a 2 A or higher adapter instead.
– Andrey Akhmetov
yesterday
9
Just get a 12V 1A wall wart. Readily available. Cheap. Problem solved. The only wrinkle may be matching the connector plug.
– Phil Freedenberg
yesterday
1
Craigslist: power adapter for sale. 5v 1A. ------------ craigslist: WTB power adapter. 12V, 8W.
– Harper
7 hours ago
add a comment |
23
I don't think $5 V × 1 A> 8 W$.
– Harry Svensson
yesterday
7
A 5V 1A wall adapter cannot provide the 8 W that the phone requires, regardless of any boost converter that you are using. As a result, the adapter is limiting its output current and the voltage sags through. Please try a 2 A or higher adapter instead.
– Andrey Akhmetov
yesterday
9
Just get a 12V 1A wall wart. Readily available. Cheap. Problem solved. The only wrinkle may be matching the connector plug.
– Phil Freedenberg
yesterday
1
Craigslist: power adapter for sale. 5v 1A. ------------ craigslist: WTB power adapter. 12V, 8W.
– Harper
7 hours ago
23
23
I don't think $5 V × 1 A> 8 W$.
– Harry Svensson
yesterday
I don't think $5 V × 1 A> 8 W$.
– Harry Svensson
yesterday
7
7
A 5V 1A wall adapter cannot provide the 8 W that the phone requires, regardless of any boost converter that you are using. As a result, the adapter is limiting its output current and the voltage sags through. Please try a 2 A or higher adapter instead.
– Andrey Akhmetov
yesterday
A 5V 1A wall adapter cannot provide the 8 W that the phone requires, regardless of any boost converter that you are using. As a result, the adapter is limiting its output current and the voltage sags through. Please try a 2 A or higher adapter instead.
– Andrey Akhmetov
yesterday
9
9
Just get a 12V 1A wall wart. Readily available. Cheap. Problem solved. The only wrinkle may be matching the connector plug.
– Phil Freedenberg
yesterday
Just get a 12V 1A wall wart. Readily available. Cheap. Problem solved. The only wrinkle may be matching the connector plug.
– Phil Freedenberg
yesterday
1
1
Craigslist: power adapter for sale. 5v 1A. ------------ craigslist: WTB power adapter. 12V, 8W.
– Harper
7 hours ago
Craigslist: power adapter for sale. 5v 1A. ------------ craigslist: WTB power adapter. 12V, 8W.
– Harper
7 hours ago
add a comment |
2 Answers
2
active
oldest
votes
Theoretically it works -
No it doesn't. In theory 5 V x 1 A = 5 W maximum from your PSU. Your phone needs 8 W and you'll lose another 1 or 2 W in the voltage booster. It doesn't work in theory and, as you've found, it doesn't work in practice.
... when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter - it shows 12 V.
That's the open-circuit or unloaded voltage.
My question is the DC coming from adapter different than DC coming from battery?
Yes. The battery has a much higher current limit.
Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Why the confusion? Check the manual for the adaptor and you'll probably find that it's indicating over-current fault.
answered yesterday
Transistor
80.1k778173
1
Hi, Thanks so much for clarifying it. It now makes complete sense to me. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
2
It possibly could but you need to ensure that it doesn't get overcharged. Read up on lead-acid battery charging to gain more understanding first.
– Transistor
yesterday
1
Thanks a lot for all your help.I will read more information on lead acid battery first, before charging. Have a nice day!
– Raool
yesterday
add a comment |
1. Theoretically it works:
Theoretically it is not correct, the power of adapter is not equal to the load power.
2.when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter
No load condition.
3. But as soon as I connect the cordless the voltage drops to 2-3 V and cordless does not power on. So its not working on load.
Obviously it will not, since the adapter is unable to provide the power required by the load.
4. I also have a 7.4 V li-ion cells which powers on the cordless fine - using the boost convertor.
The battery what you are using is having an high current delivery. that is required by the load.
5.Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Yeh, most of the Boost converters works on PWM technique.. which is going to use a switch and an inductor and capacitive network to change and discharge continuously to boost voltage... in this case the converter is going to draw current from the adapter in pulses (non-continuous).
Try the following...
Go with an readily available 12V, 1A adapter
or
Try an higher current rated adapter at 5V like 5V, 2A ... which is 10 Watts... since no boost converters are 100% efficient.
answered yesterday
Satish Singupuram
5239
Hi, Thanks so much for clarifying it. It now makes complete sense to me. I just have a doubt-- the pwm technique iis it harmful for adapter - i mean will it short circuit, or are the adaters designed for such behaviour. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
Yeh you can ... need to design an auto cut-off circuit. and the charge current should be less than 20% of AH. so in your case < 1A
– Satish Singupuram
yesterday
Hi Satish, The battery says max current 1.35amps. So i guess it should be safe. Also, could you help on whether the pwm technique does not harm the adaptor or does it? When charger indicator light is not solid...
– Raool
yesterday
It will effect so, please regulate the current to 0.5A or less.. so that you can reduce the effect on adapter, please add an high value of electrolytic capacitor between the adapter and boost converter. If 12V adapter is available please go with that.
– Satish Singupuram
yesterday
Thanks Satish, I will buy a new adaptor. That's the safest way to go.
– Raool
yesterday
add a comment |
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
});
});
}, "mathjax-editing");
StackExchange.ifUsing("editor", function () {
return StackExchange.using("schematics", function () {
StackExchange.schematics.init();
});
}, "cicuitlab");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "135"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Raool is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f413773%2fusing-5-v-adapter-to-power-12-v-cordless-phone%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
Theoretically it works -
No it doesn't. In theory 5 V x 1 A = 5 W maximum from your PSU. Your phone needs 8 W and you'll lose another 1 or 2 W in the voltage booster. It doesn't work in theory and, as you've found, it doesn't work in practice.
... when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter - it shows 12 V.
That's the open-circuit or unloaded voltage.
My question is the DC coming from adapter different than DC coming from battery?
Yes. The battery has a much higher current limit.
Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Why the confusion? Check the manual for the adaptor and you'll probably find that it's indicating over-current fault.
answered yesterday
Transistor
80.1k778173
1
Hi, Thanks so much for clarifying it. It now makes complete sense to me. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
2
It possibly could but you need to ensure that it doesn't get overcharged. Read up on lead-acid battery charging to gain more understanding first.
– Transistor
yesterday
1
Thanks a lot for all your help.I will read more information on lead acid battery first, before charging. Have a nice day!
– Raool
yesterday
add a comment |
Theoretically it works -
No it doesn't. In theory 5 V x 1 A = 5 W maximum from your PSU. Your phone needs 8 W and you'll lose another 1 or 2 W in the voltage booster. It doesn't work in theory and, as you've found, it doesn't work in practice.
... when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter - it shows 12 V.
That's the open-circuit or unloaded voltage.
My question is the DC coming from adapter different than DC coming from battery?
Yes. The battery has a much higher current limit.
Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Why the confusion? Check the manual for the adaptor and you'll probably find that it's indicating over-current fault.
answered yesterday
Transistor
80.1k778173
1
Hi, Thanks so much for clarifying it. It now makes complete sense to me. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
2
It possibly could but you need to ensure that it doesn't get overcharged. Read up on lead-acid battery charging to gain more understanding first.
– Transistor
yesterday
1
Thanks a lot for all your help.I will read more information on lead acid battery first, before charging. Have a nice day!
– Raool
yesterday
add a comment |
Theoretically it works -
No it doesn't. In theory 5 V x 1 A = 5 W maximum from your PSU. Your phone needs 8 W and you'll lose another 1 or 2 W in the voltage booster. It doesn't work in theory and, as you've found, it doesn't work in practice.
... when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter - it shows 12 V.
That's the open-circuit or unloaded voltage.
My question is the DC coming from adapter different than DC coming from battery?
Yes. The battery has a much higher current limit.
Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Why the confusion? Check the manual for the adaptor and you'll probably find that it's indicating over-current fault.
answered yesterday
Transistor
80.1k778173
Theoretically it works -
No it doesn't. In theory 5 V x 1 A = 5 W maximum from your PSU. Your phone needs 8 W and you'll lose another 1 or 2 W in the voltage booster. It doesn't work in theory and, as you've found, it doesn't work in practice.
... when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter - it shows 12 V.
That's the open-circuit or unloaded voltage.
My question is the DC coming from adapter different than DC coming from battery?
Yes. The battery has a much higher current limit.
Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Why the confusion? Check the manual for the adaptor and you'll probably find that it's indicating over-current fault.
answered yesterday
Transistor
80.1k778173
answered yesterday
Transistor
80.1k778173
answered yesterday
Transistor
80.1k778173
answered yesterday
Transistor
80.1k778173
80.1k778173
1
Hi, Thanks so much for clarifying it. It now makes complete sense to me. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
2
It possibly could but you need to ensure that it doesn't get overcharged. Read up on lead-acid battery charging to gain more understanding first.
– Transistor
yesterday
1
Thanks a lot for all your help.I will read more information on lead acid battery first, before charging. Have a nice day!
– Raool
yesterday
add a comment |
1
Hi, Thanks so much for clarifying it. It now makes complete sense to me. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
2
It possibly could but you need to ensure that it doesn't get overcharged. Read up on lead-acid battery charging to gain more understanding first.
– Transistor
yesterday
1
Thanks a lot for all your help.I will read more information on lead acid battery first, before charging. Have a nice day!
– Raool
yesterday
1
1
Hi, Thanks so much for clarifying it. It now makes complete sense to me. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
Hi, Thanks so much for clarifying it. It now makes complete sense to me. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
2
2
It possibly could but you need to ensure that it doesn't get overcharged. Read up on lead-acid battery charging to gain more understanding first.
– Transistor
yesterday
It possibly could but you need to ensure that it doesn't get overcharged. Read up on lead-acid battery charging to gain more understanding first.
– Transistor
yesterday
1
1
Thanks a lot for all your help.I will read more information on lead acid battery first, before charging. Have a nice day!
– Raool
yesterday
Thanks a lot for all your help.I will read more information on lead acid battery first, before charging. Have a nice day!
– Raool
yesterday
add a comment |
1. Theoretically it works:
Theoretically it is not correct, the power of adapter is not equal to the load power.
2.when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter
No load condition.
3. But as soon as I connect the cordless the voltage drops to 2-3 V and cordless does not power on. So its not working on load.
Obviously it will not, since the adapter is unable to provide the power required by the load.
4. I also have a 7.4 V li-ion cells which powers on the cordless fine - using the boost convertor.
The battery what you are using is having an high current delivery. that is required by the load.
5.Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Yeh, most of the Boost converters works on PWM technique.. which is going to use a switch and an inductor and capacitive network to change and discharge continuously to boost voltage... in this case the converter is going to draw current from the adapter in pulses (non-continuous).
Try the following...
Go with an readily available 12V, 1A adapter
or
Try an higher current rated adapter at 5V like 5V, 2A ... which is 10 Watts... since no boost converters are 100% efficient.
answered yesterday
Satish Singupuram
5239
Hi, Thanks so much for clarifying it. It now makes complete sense to me. I just have a doubt-- the pwm technique iis it harmful for adapter - i mean will it short circuit, or are the adaters designed for such behaviour. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
Yeh you can ... need to design an auto cut-off circuit. and the charge current should be less than 20% of AH. so in your case < 1A
– Satish Singupuram
yesterday
Hi Satish, The battery says max current 1.35amps. So i guess it should be safe. Also, could you help on whether the pwm technique does not harm the adaptor or does it? When charger indicator light is not solid...
– Raool
yesterday
It will effect so, please regulate the current to 0.5A or less.. so that you can reduce the effect on adapter, please add an high value of electrolytic capacitor between the adapter and boost converter. If 12V adapter is available please go with that.
– Satish Singupuram
yesterday
Thanks Satish, I will buy a new adaptor. That's the safest way to go.
– Raool
yesterday
add a comment |
1. Theoretically it works:
Theoretically it is not correct, the power of adapter is not equal to the load power.
2.when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter
No load condition.
3. But as soon as I connect the cordless the voltage drops to 2-3 V and cordless does not power on. So its not working on load.
Obviously it will not, since the adapter is unable to provide the power required by the load.
4. I also have a 7.4 V li-ion cells which powers on the cordless fine - using the boost convertor.
The battery what you are using is having an high current delivery. that is required by the load.
5.Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Yeh, most of the Boost converters works on PWM technique.. which is going to use a switch and an inductor and capacitive network to change and discharge continuously to boost voltage... in this case the converter is going to draw current from the adapter in pulses (non-continuous).
Try the following...
Go with an readily available 12V, 1A adapter
or
Try an higher current rated adapter at 5V like 5V, 2A ... which is 10 Watts... since no boost converters are 100% efficient.
answered yesterday
Satish Singupuram
5239
Hi, Thanks so much for clarifying it. It now makes complete sense to me. I just have a doubt-- the pwm technique iis it harmful for adapter - i mean will it short circuit, or are the adaters designed for such behaviour. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
Yeh you can ... need to design an auto cut-off circuit. and the charge current should be less than 20% of AH. so in your case < 1A
– Satish Singupuram
yesterday
Hi Satish, The battery says max current 1.35amps. So i guess it should be safe. Also, could you help on whether the pwm technique does not harm the adaptor or does it? When charger indicator light is not solid...
– Raool
yesterday
It will effect so, please regulate the current to 0.5A or less.. so that you can reduce the effect on adapter, please add an high value of electrolytic capacitor between the adapter and boost converter. If 12V adapter is available please go with that.
– Satish Singupuram
yesterday
Thanks Satish, I will buy a new adaptor. That's the safest way to go.
– Raool
yesterday
add a comment |
1. Theoretically it works:
Theoretically it is not correct, the power of adapter is not equal to the load power.
2.when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter
No load condition.
3. But as soon as I connect the cordless the voltage drops to 2-3 V and cordless does not power on. So its not working on load.
Obviously it will not, since the adapter is unable to provide the power required by the load.
4. I also have a 7.4 V li-ion cells which powers on the cordless fine - using the boost convertor.
The battery what you are using is having an high current delivery. that is required by the load.
5.Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Yeh, most of the Boost converters works on PWM technique.. which is going to use a switch and an inductor and capacitive network to change and discharge continuously to boost voltage... in this case the converter is going to draw current from the adapter in pulses (non-continuous).
Try the following...
Go with an readily available 12V, 1A adapter
or
Try an higher current rated adapter at 5V like 5V, 2A ... which is 10 Watts... since no boost converters are 100% efficient.
answered yesterday
Satish Singupuram
5239
1. Theoretically it works:
Theoretically it is not correct, the power of adapter is not equal to the load power.
2.when I connect adapter to boost convertor input and setting potentiometer to 12 V by measuring output through multimeter
No load condition.
3. But as soon as I connect the cordless the voltage drops to 2-3 V and cordless does not power on. So its not working on load.
Obviously it will not, since the adapter is unable to provide the power required by the load.
4. I also have a 7.4 V li-ion cells which powers on the cordless fine - using the boost convertor.
The battery what you are using is having an high current delivery. that is required by the load.
5.Also I noticed that the adapter indicator light is constant when charging a basic (non smartphone) phone battery but it pulsates when connected to step up convertor and cordless powered on. This made me more confused.
Yeh, most of the Boost converters works on PWM technique.. which is going to use a switch and an inductor and capacitive network to change and discharge continuously to boost voltage... in this case the converter is going to draw current from the adapter in pulses (non-continuous).
Try the following...
Go with an readily available 12V, 1A adapter
or
Try an higher current rated adapter at 5V like 5V, 2A ... which is 10 Watts... since no boost converters are 100% efficient.
answered yesterday
Satish Singupuram
5239
answered yesterday
Satish Singupuram
5239
answered yesterday
Satish Singupuram
5239
answered yesterday
Satish Singupuram
5239
5239
Hi, Thanks so much for clarifying it. It now makes complete sense to me. I just have a doubt-- the pwm technique iis it harmful for adapter - i mean will it short circuit, or are the adaters designed for such behaviour. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
Yeh you can ... need to design an auto cut-off circuit. and the charge current should be less than 20% of AH. so in your case < 1A
– Satish Singupuram
yesterday
Hi Satish, The battery says max current 1.35amps. So i guess it should be safe. Also, could you help on whether the pwm technique does not harm the adaptor or does it? When charger indicator light is not solid...
– Raool
yesterday
It will effect so, please regulate the current to 0.5A or less.. so that you can reduce the effect on adapter, please add an high value of electrolytic capacitor between the adapter and boost converter. If 12V adapter is available please go with that.
– Satish Singupuram
yesterday
Thanks Satish, I will buy a new adaptor. That's the safest way to go.
– Raool
yesterday
add a comment |
Hi, Thanks so much for clarifying it. It now makes complete sense to me. I just have a doubt-- the pwm technique iis it harmful for adapter - i mean will it short circuit, or are the adaters designed for such behaviour. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
Yeh you can ... need to design an auto cut-off circuit. and the charge current should be less than 20% of AH. so in your case < 1A
– Satish Singupuram
yesterday
Hi Satish, The battery says max current 1.35amps. So i guess it should be safe. Also, could you help on whether the pwm technique does not harm the adaptor or does it? When charger indicator light is not solid...
– Raool
yesterday
It will effect so, please regulate the current to 0.5A or less.. so that you can reduce the effect on adapter, please add an high value of electrolytic capacitor between the adapter and boost converter. If 12V adapter is available please go with that.
– Satish Singupuram
yesterday
Thanks Satish, I will buy a new adaptor. That's the safest way to go.
– Raool
yesterday
Hi, Thanks so much for clarifying it. It now makes complete sense to me. I just have a doubt-- the pwm technique iis it harmful for adapter - i mean will it short circuit, or are the adaters designed for such behaviour. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
Hi, Thanks so much for clarifying it. It now makes complete sense to me. I just have a doubt-- the pwm technique iis it harmful for adapter - i mean will it short circuit, or are the adaters designed for such behaviour. Also, can i ask whether this arrangement- (5v 1a adaptor and a dc booster)- can be used to charge a 6v 4.5ah lead acid battery- if i increase voltage to 7v for charging battery -- (Its printed- 7v for cyclic use on battery)
– Raool
yesterday
Yeh you can ... need to design an auto cut-off circuit. and the charge current should be less than 20% of AH. so in your case < 1A
– Satish Singupuram
yesterday
Yeh you can ... need to design an auto cut-off circuit. and the charge current should be less than 20% of AH. so in your case < 1A
– Satish Singupuram
yesterday
Hi Satish, The battery says max current 1.35amps. So i guess it should be safe. Also, could you help on whether the pwm technique does not harm the adaptor or does it? When charger indicator light is not solid...
– Raool
yesterday
Hi Satish, The battery says max current 1.35amps. So i guess it should be safe. Also, could you help on whether the pwm technique does not harm the adaptor or does it? When charger indicator light is not solid...
– Raool
yesterday
It will effect so, please regulate the current to 0.5A or less.. so that you can reduce the effect on adapter, please add an high value of electrolytic capacitor between the adapter and boost converter. If 12V adapter is available please go with that.
– Satish Singupuram
yesterday
It will effect so, please regulate the current to 0.5A or less.. so that you can reduce the effect on adapter, please add an high value of electrolytic capacitor between the adapter and boost converter. If 12V adapter is available please go with that.
– Satish Singupuram
yesterday
Thanks Satish, I will buy a new adaptor. That's the safest way to go.
– Raool
yesterday
Thanks Satish, I will buy a new adaptor. That's the safest way to go.
– Raool
yesterday
add a comment |
Raool is a new contributor. Be nice, and check out our Code of Conduct.
Raool is a new contributor. Be nice, and check out our Code of Conduct.
Raool is a new contributor. Be nice, and check out our Code of Conduct.
Raool is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Electrical Engineering Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2felectronics.stackexchange.com%2fquestions%2f413773%2fusing-5-v-adapter-to-power-12-v-cordless-phone%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
23
I don't think $5 V × 1 A> 8 W$.
– Harry Svensson
yesterday
7
A 5V 1A wall adapter cannot provide the 8 W that the phone requires, regardless of any boost converter that you are using. As a result, the adapter is limiting its output current and the voltage sags through. Please try a 2 A or higher adapter instead.
– Andrey Akhmetov
yesterday
9
Just get a 12V 1A wall wart. Readily available. Cheap. Problem solved. The only wrinkle may be matching the connector plug.
– Phil Freedenberg
yesterday
1
Craigslist: power adapter for sale. 5v 1A. ------------ craigslist: WTB power adapter. 12V, 8W.
– Harper
7 hours ago