steveplant123
- Mar 28, 2013
- 2
- Joined
- Mar 28, 2013
- Messages
- 2
I am building a very simple bench power supply based around the LM317 chip (2amp version)
I want to monitor output voltage and current with a couple of digital LED modules.
I have powered these using a second (100mA) LM317.
The problem I get is that I get a 'dead short' when the ammeter module is in the circuit. (whichever way I connect it in)
Also the DVM module will not read the correct value!
The only way I can get the system to work correctly is by powering the Voltmeter and Ammeter with separate 9V batteries.(which does demonstrate my PSU wiring is correct!)
As I really don't want to use batteries any suggestions as to how I can power these two meter modules without them 'interfering' with each other would be much appreciated.
Please be aware that my knowledge of electronics is very basic (as is probably demonstrated by this question!)
Many thanks in advance, Steve P
I want to monitor output voltage and current with a couple of digital LED modules.
I have powered these using a second (100mA) LM317.
The problem I get is that I get a 'dead short' when the ammeter module is in the circuit. (whichever way I connect it in)
Also the DVM module will not read the correct value!
The only way I can get the system to work correctly is by powering the Voltmeter and Ammeter with separate 9V batteries.(which does demonstrate my PSU wiring is correct!)
As I really don't want to use batteries any suggestions as to how I can power these two meter modules without them 'interfering' with each other would be much appreciated.
Please be aware that my knowledge of electronics is very basic (as is probably demonstrated by this question!)
Many thanks in advance, Steve P
Last edited: