Solar charger in commercial application based on an LM317 IC [closed]
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$begingroup$
I have been working on a project of a commercial LoRaWan node. I want it to be powered by 3.7 battery and I consider to add a solar charger. For now, I have implemented a circuit based on an LTC3652 IC and it works quite good.
I found such solution today. What do you think of this one?
I'm not hiding that this solution is way cheaper and easier. Have you ever dealt with this circuit? What's your experience on this one?
Is it safe to implement this circuit in commercial solution or you think I'd better stay with the circuit mentioned in the beginning?
lm317
asked Feb 14 at 10:33
Y. MarkovY. Markov
647
$endgroup$
closed as too broad by Chris Stratton, Edgar Brown, Sean Houlihane, Finbarr, Bimpelrekkie Feb 18 at 12:43
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
add a comment |
$begingroup$
I have been working on a project of a commercial LoRaWan node. I want it to be powered by 3.7 battery and I consider to add a solar charger. For now, I have implemented a circuit based on an LTC3652 IC and it works quite good.
I found such solution today. What do you think of this one?
I'm not hiding that this solution is way cheaper and easier. Have you ever dealt with this circuit? What's your experience on this one?
Is it safe to implement this circuit in commercial solution or you think I'd better stay with the circuit mentioned in the beginning?
lm317
asked Feb 14 at 10:33
Y. MarkovY. Markov
647
$endgroup$
closed as too broad by Chris Stratton, Edgar Brown, Sean Houlihane, Finbarr, Bimpelrekkie Feb 18 at 12:43
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
5
$begingroup$
You first mention a 3.7 V battery so that is likely a Lithium based cell. The circuit shows a 6 V battery which is likely a Lead Acid type. You cannot and should not just charge a Lithium based cell with a charging circuit designed for a Lead Acid battery. Lead Acid batteries are much less "picky" with regard to how you charge them so then you can use this simple circuit. For Lithium cells you should not, you must use a charging circuit which is designed for Lithium cells. Unless you do not mind your battery overheating/smoking/catching fire etc.
$endgroup$
– Bimpelrekkie
Feb 14 at 11:09
$begingroup$
This is not a good design. Bypass capacitors are missing and T1 should have a base pulldown resistor of 100K or so. Voltage clamp is not effective until about 7.4 volts. This may work for 7.4 volt NiMH batteries or 6 volt lead-acid batteries.
$endgroup$
– Sparky256
Feb 15 at 2:20
$begingroup$
LM317 was an amazing IC when it first came out. Nonetheless, and with no ill-will directed at the original designers (who were giants among men) at this point, I would recommend that it not be used for new designs, regardless of its official production status.
$endgroup$
– mkeith
Feb 16 at 2:35
add a comment |
$begingroup$
I have been working on a project of a commercial LoRaWan node. I want it to be powered by 3.7 battery and I consider to add a solar charger. For now, I have implemented a circuit based on an LTC3652 IC and it works quite good.
I found such solution today. What do you think of this one?
I'm not hiding that this solution is way cheaper and easier. Have you ever dealt with this circuit? What's your experience on this one?
Is it safe to implement this circuit in commercial solution or you think I'd better stay with the circuit mentioned in the beginning?
lm317
asked Feb 14 at 10:33
Y. MarkovY. Markov
647
$endgroup$
I have been working on a project of a commercial LoRaWan node. I want it to be powered by 3.7 battery and I consider to add a solar charger. For now, I have implemented a circuit based on an LTC3652 IC and it works quite good.
I found such solution today. What do you think of this one?
I'm not hiding that this solution is way cheaper and easier. Have you ever dealt with this circuit? What's your experience on this one?
Is it safe to implement this circuit in commercial solution or you think I'd better stay with the circuit mentioned in the beginning?
lm317
lm317
asked Feb 14 at 10:33
Y. MarkovY. Markov
647
asked Feb 14 at 10:33
Y. MarkovY. Markov
647
asked Feb 14 at 10:33
Y. MarkovY. Markov
647
asked Feb 14 at 10:33
Y. MarkovY. Markov
647
asked Feb 14 at 10:33
Y. MarkovY. Markov
647
647
closed as too broad by Chris Stratton, Edgar Brown, Sean Houlihane, Finbarr, Bimpelrekkie Feb 18 at 12:43
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
closed as too broad by Chris Stratton, Edgar Brown, Sean Houlihane, Finbarr, Bimpelrekkie Feb 18 at 12:43
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
5
$begingroup$
You first mention a 3.7 V battery so that is likely a Lithium based cell. The circuit shows a 6 V battery which is likely a Lead Acid type. You cannot and should not just charge a Lithium based cell with a charging circuit designed for a Lead Acid battery. Lead Acid batteries are much less "picky" with regard to how you charge them so then you can use this simple circuit. For Lithium cells you should not, you must use a charging circuit which is designed for Lithium cells. Unless you do not mind your battery overheating/smoking/catching fire etc.
$endgroup$
– Bimpelrekkie
Feb 14 at 11:09
$begingroup$
This is not a good design. Bypass capacitors are missing and T1 should have a base pulldown resistor of 100K or so. Voltage clamp is not effective until about 7.4 volts. This may work for 7.4 volt NiMH batteries or 6 volt lead-acid batteries.
$endgroup$
– Sparky256
Feb 15 at 2:20
$begingroup$
LM317 was an amazing IC when it first came out. Nonetheless, and with no ill-will directed at the original designers (who were giants among men) at this point, I would recommend that it not be used for new designs, regardless of its official production status.
$endgroup$
– mkeith
Feb 16 at 2:35
add a comment |
5
$begingroup$
You first mention a 3.7 V battery so that is likely a Lithium based cell. The circuit shows a 6 V battery which is likely a Lead Acid type. You cannot and should not just charge a Lithium based cell with a charging circuit designed for a Lead Acid battery. Lead Acid batteries are much less "picky" with regard to how you charge them so then you can use this simple circuit. For Lithium cells you should not, you must use a charging circuit which is designed for Lithium cells. Unless you do not mind your battery overheating/smoking/catching fire etc.
$endgroup$
– Bimpelrekkie
Feb 14 at 11:09
$begingroup$
This is not a good design. Bypass capacitors are missing and T1 should have a base pulldown resistor of 100K or so. Voltage clamp is not effective until about 7.4 volts. This may work for 7.4 volt NiMH batteries or 6 volt lead-acid batteries.
$endgroup$
– Sparky256
Feb 15 at 2:20
$begingroup$
LM317 was an amazing IC when it first came out. Nonetheless, and with no ill-will directed at the original designers (who were giants among men) at this point, I would recommend that it not be used for new designs, regardless of its official production status.
$endgroup$
– mkeith
Feb 16 at 2:35
5
5
$begingroup$
You first mention a 3.7 V battery so that is likely a Lithium based cell. The circuit shows a 6 V battery which is likely a Lead Acid type. You cannot and should not just charge a Lithium based cell with a charging circuit designed for a Lead Acid battery. Lead Acid batteries are much less "picky" with regard to how you charge them so then you can use this simple circuit. For Lithium cells you should not, you must use a charging circuit which is designed for Lithium cells. Unless you do not mind your battery overheating/smoking/catching fire etc.
$endgroup$
– Bimpelrekkie
Feb 14 at 11:09
$begingroup$
You first mention a 3.7 V battery so that is likely a Lithium based cell. The circuit shows a 6 V battery which is likely a Lead Acid type. You cannot and should not just charge a Lithium based cell with a charging circuit designed for a Lead Acid battery. Lead Acid batteries are much less "picky" with regard to how you charge them so then you can use this simple circuit. For Lithium cells you should not, you must use a charging circuit which is designed for Lithium cells. Unless you do not mind your battery overheating/smoking/catching fire etc.
$endgroup$
– Bimpelrekkie
Feb 14 at 11:09
$begingroup$
This is not a good design. Bypass capacitors are missing and T1 should have a base pulldown resistor of 100K or so. Voltage clamp is not effective until about 7.4 volts. This may work for 7.4 volt NiMH batteries or 6 volt lead-acid batteries.
$endgroup$
– Sparky256
Feb 15 at 2:20
$begingroup$
This is not a good design. Bypass capacitors are missing and T1 should have a base pulldown resistor of 100K or so. Voltage clamp is not effective until about 7.4 volts. This may work for 7.4 volt NiMH batteries or 6 volt lead-acid batteries.
$endgroup$
– Sparky256
Feb 15 at 2:20
$begingroup$
LM317 was an amazing IC when it first came out. Nonetheless, and with no ill-will directed at the original designers (who were giants among men) at this point, I would recommend that it not be used for new designs, regardless of its official production status.
$endgroup$
– mkeith
Feb 16 at 2:35
$begingroup$
LM317 was an amazing IC when it first came out. Nonetheless, and with no ill-will directed at the original designers (who were giants among men) at this point, I would recommend that it not be used for new designs, regardless of its official production status.
$endgroup$
– mkeith
Feb 16 at 2:35
add a comment |
2 Answers
2
active
oldest
votes
$begingroup$
Since you say this is for a comnercial product, I'll be up front about this: Given the choice between buying your product with an LM317 regulator or a product from your competition using the LTC3652, I'd rather buy from your competition.
You are saving a few cents, and delivering an inferior product.
The LM317 is in all ways inferior to the LTC3652.
The LTC3652 uses Maximum power point tracking (MPPT) to make the best use of the power from the panel. The LM317 can't.
The LTC3652 is an efficient switching regulator so as not to waste power from the solar panel. The LM317 is an inefficient linear regulator, whose efficiency gets worse when the panel provides more power.
The LTC3652 is a charge controller. It has selectable charge termination, and maintains the battery at full charge by monitoring the voltage and switching back to charge mode when needed. Your LM317 circuit has charge termination, but it depends on the properties of a zener diode and a transistor - making it properly match your battery could be difficult.
The LTC3652 can easily set the charge current - the datasheet tells you how. The LM317 circuit you have can also set the charge current - does the source of your circuit tell you how?
That LM317 circuit is simpler and easier than the LTC3652 in the same sense that it is simpler and easier to light a campfire on the kitchen floor rather than installing a stove and oven. It's cheaper, but it sure ain't better.
As already mentioned in the comnents, the LM317 circuit is not a good choice for lithium batteries.
The LTC3652 isn't either, except for LiFePO4 which is explicitly mentioned on Analog's web page.
Both circuits seem to be better suited to lead acid batteries.
edited Feb 14 at 17:18
longneck
23516
answered Feb 14 at 12:24
JREJRE
23.6k54379
$endgroup$
$begingroup$
you're talking about a 7$ chip where entire lorawan modules powered by an esp32 go for <$20. Adafruit sells a solar charging breakout board that uses MCP73871, which seems quite well suited to the task. (and only ~2$ on digikey vs ~7$)
$endgroup$
– Aaron
Feb 14 at 15:06
$begingroup$
The LM317 was designed to be a linear regulator. It was never intended to be a solar-panel battery charger. You are criticizing an orange for not being an Apple.
$endgroup$
– Edgar Brown
Feb 16 at 5:30
add a comment |
$begingroup$
Commercial use and outdated, inefficient linear regulators are not good partners.
Modern switching supplies cost little more and when factoring in things like heatsinks, can and often do cost less overall.
For lithium batteries, a battery manager designed for such batteries is an essential. If you don't use one, expect lawsuits as you're essentially creating a firebomb. Lithium batteries are great but, improperly handled, they are dangerous.
If you're asking such questions, you really need to hire an experienced design engineer to do the design for you.
edited Feb 16 at 23:48
SamGibson
11.8k41739
answered Feb 16 at 0:47
PeterPeter
211
$endgroup$
2
$begingroup$
I agree with you. HOWEVER, let's take a moment to appreciate how good the LM317 was for its time (1976). It has been continuously in production for over 40 years! It is older than most of the people who ask questions on this site (but not older than the people who answer them, I suspect).
$endgroup$
– mkeith
Feb 16 at 2:39
1
$begingroup$
@mkeith The dynamic Widlar-Dobkin duo made the LM317 do double duty- a change to the metalization mask only resulted in the LM395 "ultra reliable power transistor", it was otherwise the same die.
$endgroup$
– Spehro Pefhany
Feb 17 at 0:07
$begingroup$
Ha ha.... mkeith must be more than 40 years old.
$endgroup$
– soosai steven
Feb 17 at 2:45
add a comment |
2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
Since you say this is for a comnercial product, I'll be up front about this: Given the choice between buying your product with an LM317 regulator or a product from your competition using the LTC3652, I'd rather buy from your competition.
You are saving a few cents, and delivering an inferior product.
The LM317 is in all ways inferior to the LTC3652.
The LTC3652 uses Maximum power point tracking (MPPT) to make the best use of the power from the panel. The LM317 can't.
The LTC3652 is an efficient switching regulator so as not to waste power from the solar panel. The LM317 is an inefficient linear regulator, whose efficiency gets worse when the panel provides more power.
The LTC3652 is a charge controller. It has selectable charge termination, and maintains the battery at full charge by monitoring the voltage and switching back to charge mode when needed. Your LM317 circuit has charge termination, but it depends on the properties of a zener diode and a transistor - making it properly match your battery could be difficult.
The LTC3652 can easily set the charge current - the datasheet tells you how. The LM317 circuit you have can also set the charge current - does the source of your circuit tell you how?
That LM317 circuit is simpler and easier than the LTC3652 in the same sense that it is simpler and easier to light a campfire on the kitchen floor rather than installing a stove and oven. It's cheaper, but it sure ain't better.
As already mentioned in the comnents, the LM317 circuit is not a good choice for lithium batteries.
The LTC3652 isn't either, except for LiFePO4 which is explicitly mentioned on Analog's web page.
Both circuits seem to be better suited to lead acid batteries.
edited Feb 14 at 17:18
longneck
23516
answered Feb 14 at 12:24
JREJRE
23.6k54379
$endgroup$
$begingroup$
you're talking about a 7$ chip where entire lorawan modules powered by an esp32 go for <$20. Adafruit sells a solar charging breakout board that uses MCP73871, which seems quite well suited to the task. (and only ~2$ on digikey vs ~7$)
$endgroup$
– Aaron
Feb 14 at 15:06
$begingroup$
The LM317 was designed to be a linear regulator. It was never intended to be a solar-panel battery charger. You are criticizing an orange for not being an Apple.
$endgroup$
– Edgar Brown
Feb 16 at 5:30
add a comment |
$begingroup$
Since you say this is for a comnercial product, I'll be up front about this: Given the choice between buying your product with an LM317 regulator or a product from your competition using the LTC3652, I'd rather buy from your competition.
You are saving a few cents, and delivering an inferior product.
The LM317 is in all ways inferior to the LTC3652.
The LTC3652 uses Maximum power point tracking (MPPT) to make the best use of the power from the panel. The LM317 can't.
The LTC3652 is an efficient switching regulator so as not to waste power from the solar panel. The LM317 is an inefficient linear regulator, whose efficiency gets worse when the panel provides more power.
The LTC3652 is a charge controller. It has selectable charge termination, and maintains the battery at full charge by monitoring the voltage and switching back to charge mode when needed. Your LM317 circuit has charge termination, but it depends on the properties of a zener diode and a transistor - making it properly match your battery could be difficult.
The LTC3652 can easily set the charge current - the datasheet tells you how. The LM317 circuit you have can also set the charge current - does the source of your circuit tell you how?
That LM317 circuit is simpler and easier than the LTC3652 in the same sense that it is simpler and easier to light a campfire on the kitchen floor rather than installing a stove and oven. It's cheaper, but it sure ain't better.
As already mentioned in the comnents, the LM317 circuit is not a good choice for lithium batteries.
The LTC3652 isn't either, except for LiFePO4 which is explicitly mentioned on Analog's web page.
Both circuits seem to be better suited to lead acid batteries.
edited Feb 14 at 17:18
longneck
23516
answered Feb 14 at 12:24
JREJRE
23.6k54379
$endgroup$
$begingroup$
you're talking about a 7$ chip where entire lorawan modules powered by an esp32 go for <$20. Adafruit sells a solar charging breakout board that uses MCP73871, which seems quite well suited to the task. (and only ~2$ on digikey vs ~7$)
$endgroup$
– Aaron
Feb 14 at 15:06
$begingroup$
The LM317 was designed to be a linear regulator. It was never intended to be a solar-panel battery charger. You are criticizing an orange for not being an Apple.
$endgroup$
– Edgar Brown
Feb 16 at 5:30
add a comment |
$begingroup$
Since you say this is for a comnercial product, I'll be up front about this: Given the choice between buying your product with an LM317 regulator or a product from your competition using the LTC3652, I'd rather buy from your competition.
You are saving a few cents, and delivering an inferior product.
The LM317 is in all ways inferior to the LTC3652.
The LTC3652 uses Maximum power point tracking (MPPT) to make the best use of the power from the panel. The LM317 can't.
The LTC3652 is an efficient switching regulator so as not to waste power from the solar panel. The LM317 is an inefficient linear regulator, whose efficiency gets worse when the panel provides more power.
The LTC3652 is a charge controller. It has selectable charge termination, and maintains the battery at full charge by monitoring the voltage and switching back to charge mode when needed. Your LM317 circuit has charge termination, but it depends on the properties of a zener diode and a transistor - making it properly match your battery could be difficult.
The LTC3652 can easily set the charge current - the datasheet tells you how. The LM317 circuit you have can also set the charge current - does the source of your circuit tell you how?
That LM317 circuit is simpler and easier than the LTC3652 in the same sense that it is simpler and easier to light a campfire on the kitchen floor rather than installing a stove and oven. It's cheaper, but it sure ain't better.
As already mentioned in the comnents, the LM317 circuit is not a good choice for lithium batteries.
The LTC3652 isn't either, except for LiFePO4 which is explicitly mentioned on Analog's web page.
Both circuits seem to be better suited to lead acid batteries.
edited Feb 14 at 17:18
longneck
23516
answered Feb 14 at 12:24
JREJRE
23.6k54379
$endgroup$
Since you say this is for a comnercial product, I'll be up front about this: Given the choice between buying your product with an LM317 regulator or a product from your competition using the LTC3652, I'd rather buy from your competition.
You are saving a few cents, and delivering an inferior product.
The LM317 is in all ways inferior to the LTC3652.
The LTC3652 uses Maximum power point tracking (MPPT) to make the best use of the power from the panel. The LM317 can't.
The LTC3652 is an efficient switching regulator so as not to waste power from the solar panel. The LM317 is an inefficient linear regulator, whose efficiency gets worse when the panel provides more power.
The LTC3652 is a charge controller. It has selectable charge termination, and maintains the battery at full charge by monitoring the voltage and switching back to charge mode when needed. Your LM317 circuit has charge termination, but it depends on the properties of a zener diode and a transistor - making it properly match your battery could be difficult.
The LTC3652 can easily set the charge current - the datasheet tells you how. The LM317 circuit you have can also set the charge current - does the source of your circuit tell you how?
That LM317 circuit is simpler and easier than the LTC3652 in the same sense that it is simpler and easier to light a campfire on the kitchen floor rather than installing a stove and oven. It's cheaper, but it sure ain't better.
As already mentioned in the comnents, the LM317 circuit is not a good choice for lithium batteries.
The LTC3652 isn't either, except for LiFePO4 which is explicitly mentioned on Analog's web page.
Both circuits seem to be better suited to lead acid batteries.
edited Feb 14 at 17:18
longneck
23516
answered Feb 14 at 12:24
JREJRE
23.6k54379
edited Feb 14 at 17:18
longneck
23516
edited Feb 14 at 17:18
longneck
23516
edited Feb 14 at 17:18
longneck
23516
23516
answered Feb 14 at 12:24
JREJRE
23.6k54379
answered Feb 14 at 12:24
JREJRE
23.6k54379
answered Feb 14 at 12:24
JREJRE
23.6k54379
23.6k54379
$begingroup$
you're talking about a 7$ chip where entire lorawan modules powered by an esp32 go for <$20. Adafruit sells a solar charging breakout board that uses MCP73871, which seems quite well suited to the task. (and only ~2$ on digikey vs ~7$)
$endgroup$
– Aaron
Feb 14 at 15:06
$begingroup$
The LM317 was designed to be a linear regulator. It was never intended to be a solar-panel battery charger. You are criticizing an orange for not being an Apple.
$endgroup$
– Edgar Brown
Feb 16 at 5:30
add a comment |
$begingroup$
you're talking about a 7$ chip where entire lorawan modules powered by an esp32 go for <$20. Adafruit sells a solar charging breakout board that uses MCP73871, which seems quite well suited to the task. (and only ~2$ on digikey vs ~7$)
$endgroup$
– Aaron
Feb 14 at 15:06
$begingroup$
The LM317 was designed to be a linear regulator. It was never intended to be a solar-panel battery charger. You are criticizing an orange for not being an Apple.
$endgroup$
– Edgar Brown
Feb 16 at 5:30
$begingroup$
you're talking about a 7$ chip where entire lorawan modules powered by an esp32 go for <$20. Adafruit sells a solar charging breakout board that uses MCP73871, which seems quite well suited to the task. (and only ~2$ on digikey vs ~7$)
$endgroup$
– Aaron
Feb 14 at 15:06
$begingroup$
you're talking about a 7$ chip where entire lorawan modules powered by an esp32 go for <$20. Adafruit sells a solar charging breakout board that uses MCP73871, which seems quite well suited to the task. (and only ~2$ on digikey vs ~7$)
$endgroup$
– Aaron
Feb 14 at 15:06
$begingroup$
The LM317 was designed to be a linear regulator. It was never intended to be a solar-panel battery charger. You are criticizing an orange for not being an Apple.
$endgroup$
– Edgar Brown
Feb 16 at 5:30
$begingroup$
The LM317 was designed to be a linear regulator. It was never intended to be a solar-panel battery charger. You are criticizing an orange for not being an Apple.
$endgroup$
– Edgar Brown
Feb 16 at 5:30
add a comment |
$begingroup$
Commercial use and outdated, inefficient linear regulators are not good partners.
Modern switching supplies cost little more and when factoring in things like heatsinks, can and often do cost less overall.
For lithium batteries, a battery manager designed for such batteries is an essential. If you don't use one, expect lawsuits as you're essentially creating a firebomb. Lithium batteries are great but, improperly handled, they are dangerous.
If you're asking such questions, you really need to hire an experienced design engineer to do the design for you.
edited Feb 16 at 23:48
SamGibson
11.8k41739
answered Feb 16 at 0:47
PeterPeter
211
$endgroup$
2
$begingroup$
I agree with you. HOWEVER, let's take a moment to appreciate how good the LM317 was for its time (1976). It has been continuously in production for over 40 years! It is older than most of the people who ask questions on this site (but not older than the people who answer them, I suspect).
$endgroup$
– mkeith
Feb 16 at 2:39
1
$begingroup$
@mkeith The dynamic Widlar-Dobkin duo made the LM317 do double duty- a change to the metalization mask only resulted in the LM395 "ultra reliable power transistor", it was otherwise the same die.
$endgroup$
– Spehro Pefhany
Feb 17 at 0:07
$begingroup$
Ha ha.... mkeith must be more than 40 years old.
$endgroup$
– soosai steven
Feb 17 at 2:45
add a comment |
$begingroup$
Commercial use and outdated, inefficient linear regulators are not good partners.
Modern switching supplies cost little more and when factoring in things like heatsinks, can and often do cost less overall.
For lithium batteries, a battery manager designed for such batteries is an essential. If you don't use one, expect lawsuits as you're essentially creating a firebomb. Lithium batteries are great but, improperly handled, they are dangerous.
If you're asking such questions, you really need to hire an experienced design engineer to do the design for you.
edited Feb 16 at 23:48
SamGibson
11.8k41739
answered Feb 16 at 0:47
PeterPeter
211
$endgroup$
2
$begingroup$
I agree with you. HOWEVER, let's take a moment to appreciate how good the LM317 was for its time (1976). It has been continuously in production for over 40 years! It is older than most of the people who ask questions on this site (but not older than the people who answer them, I suspect).
$endgroup$
– mkeith
Feb 16 at 2:39
1
$begingroup$
@mkeith The dynamic Widlar-Dobkin duo made the LM317 do double duty- a change to the metalization mask only resulted in the LM395 "ultra reliable power transistor", it was otherwise the same die.
$endgroup$
– Spehro Pefhany
Feb 17 at 0:07
$begingroup$
Ha ha.... mkeith must be more than 40 years old.
$endgroup$
– soosai steven
Feb 17 at 2:45
add a comment |
$begingroup$
Commercial use and outdated, inefficient linear regulators are not good partners.
Modern switching supplies cost little more and when factoring in things like heatsinks, can and often do cost less overall.
For lithium batteries, a battery manager designed for such batteries is an essential. If you don't use one, expect lawsuits as you're essentially creating a firebomb. Lithium batteries are great but, improperly handled, they are dangerous.
If you're asking such questions, you really need to hire an experienced design engineer to do the design for you.
edited Feb 16 at 23:48
SamGibson
11.8k41739
answered Feb 16 at 0:47
PeterPeter
211
$endgroup$
Commercial use and outdated, inefficient linear regulators are not good partners.
Modern switching supplies cost little more and when factoring in things like heatsinks, can and often do cost less overall.
For lithium batteries, a battery manager designed for such batteries is an essential. If you don't use one, expect lawsuits as you're essentially creating a firebomb. Lithium batteries are great but, improperly handled, they are dangerous.
If you're asking such questions, you really need to hire an experienced design engineer to do the design for you.
edited Feb 16 at 23:48
SamGibson
11.8k41739
answered Feb 16 at 0:47
PeterPeter
211
edited Feb 16 at 23:48
SamGibson
11.8k41739
edited Feb 16 at 23:48
SamGibson
11.8k41739
edited Feb 16 at 23:48
SamGibson
11.8k41739
11.8k41739
answered Feb 16 at 0:47
PeterPeter
211
answered Feb 16 at 0:47
PeterPeter
211
answered Feb 16 at 0:47
PeterPeter
211
211
2
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I agree with you. HOWEVER, let's take a moment to appreciate how good the LM317 was for its time (1976). It has been continuously in production for over 40 years! It is older than most of the people who ask questions on this site (but not older than the people who answer them, I suspect).
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– mkeith
Feb 16 at 2:39
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@mkeith The dynamic Widlar-Dobkin duo made the LM317 do double duty- a change to the metalization mask only resulted in the LM395 "ultra reliable power transistor", it was otherwise the same die.
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– Spehro Pefhany
Feb 17 at 0:07
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Ha ha.... mkeith must be more than 40 years old.
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– soosai steven
Feb 17 at 2:45
add a comment |
2
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I agree with you. HOWEVER, let's take a moment to appreciate how good the LM317 was for its time (1976). It has been continuously in production for over 40 years! It is older than most of the people who ask questions on this site (but not older than the people who answer them, I suspect).
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– mkeith
Feb 16 at 2:39
1
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@mkeith The dynamic Widlar-Dobkin duo made the LM317 do double duty- a change to the metalization mask only resulted in the LM395 "ultra reliable power transistor", it was otherwise the same die.
$endgroup$
– Spehro Pefhany
Feb 17 at 0:07
$begingroup$
Ha ha.... mkeith must be more than 40 years old.
$endgroup$
– soosai steven
Feb 17 at 2:45
2
2
$begingroup$
I agree with you. HOWEVER, let's take a moment to appreciate how good the LM317 was for its time (1976). It has been continuously in production for over 40 years! It is older than most of the people who ask questions on this site (but not older than the people who answer them, I suspect).
$endgroup$
– mkeith
Feb 16 at 2:39
$begingroup$
I agree with you. HOWEVER, let's take a moment to appreciate how good the LM317 was for its time (1976). It has been continuously in production for over 40 years! It is older than most of the people who ask questions on this site (but not older than the people who answer them, I suspect).
$endgroup$
– mkeith
Feb 16 at 2:39
1
1
$begingroup$
@mkeith The dynamic Widlar-Dobkin duo made the LM317 do double duty- a change to the metalization mask only resulted in the LM395 "ultra reliable power transistor", it was otherwise the same die.
$endgroup$
– Spehro Pefhany
Feb 17 at 0:07
$begingroup$
@mkeith The dynamic Widlar-Dobkin duo made the LM317 do double duty- a change to the metalization mask only resulted in the LM395 "ultra reliable power transistor", it was otherwise the same die.
$endgroup$
– Spehro Pefhany
Feb 17 at 0:07
$begingroup$
Ha ha.... mkeith must be more than 40 years old.
$endgroup$
– soosai steven
Feb 17 at 2:45
$begingroup$
Ha ha.... mkeith must be more than 40 years old.
$endgroup$
– soosai steven
Feb 17 at 2:45
add a comment |
5
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You first mention a 3.7 V battery so that is likely a Lithium based cell. The circuit shows a 6 V battery which is likely a Lead Acid type. You cannot and should not just charge a Lithium based cell with a charging circuit designed for a Lead Acid battery. Lead Acid batteries are much less "picky" with regard to how you charge them so then you can use this simple circuit. For Lithium cells you should not, you must use a charging circuit which is designed for Lithium cells. Unless you do not mind your battery overheating/smoking/catching fire etc.
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– Bimpelrekkie
Feb 14 at 11:09
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This is not a good design. Bypass capacitors are missing and T1 should have a base pulldown resistor of 100K or so. Voltage clamp is not effective until about 7.4 volts. This may work for 7.4 volt NiMH batteries or 6 volt lead-acid batteries.
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– Sparky256
Feb 15 at 2:20
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LM317 was an amazing IC when it first came out. Nonetheless, and with no ill-will directed at the original designers (who were giants among men) at this point, I would recommend that it not be used for new designs, regardless of its official production status.
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– mkeith
Feb 16 at 2:35