Hi!
I'm building an ESR meter, a classic one with an analog microammeter for indication.
The problem is, the circuit is designed for a 50 uA microammeter. I only have a 200uA meter.
I get 1/4 full scale reading for 0ohms, shorted terminals (that's good because at 0 ohms means 50uA that is 1/4 of my meter's scale)
If I remove the "zero adjust" potentiometer and a series resistance, I can get a maximum of 110uA out of the circuit, but that is 1/2 of my meter's scale....
For full scale I need 200uA.
How can I increase the current to reach a full scale reading? By using some kind of DC current amplifier? Or maybe a voltage doubler?
I'll upload photos later, the question is simple: How can I adapt a higher amperage ammeter to work in a lower amperage circuit?
I'm building an ESR meter, a classic one with an analog microammeter for indication.
The problem is, the circuit is designed for a 50 uA microammeter. I only have a 200uA meter.
I get 1/4 full scale reading for 0ohms, shorted terminals (that's good because at 0 ohms means 50uA that is 1/4 of my meter's scale)
If I remove the "zero adjust" potentiometer and a series resistance, I can get a maximum of 110uA out of the circuit, but that is 1/2 of my meter's scale....
For full scale I need 200uA.
How can I increase the current to reach a full scale reading? By using some kind of DC current amplifier? Or maybe a voltage doubler?
I'll upload photos later, the question is simple: How can I adapt a higher amperage ammeter to work in a lower amperage circuit?
