Hi All
New to this forum and wondering if anybody can explain:
A have this old traditional car battery charger. Works fine but the build-in analog ammeter got stuck. 230V in and 12/24 V out.
Got the idea of digital replacement and fitted a digital voltmeter at the same time (to monitor battery and check behavior when charger is shut off). Voltmeter works as expected.
The ammeter is digital, connected to 12v pos & neg, to power it, and to each side of the shunt (200A, 75 mV) to measure amps. Terminals marked 5V, O, IN- and IN+.
Whenever power is on, no matter if the measuring wires are connected, the digits jumps about. All sorts of readings, even negative.
Conncting the measuring wires will change the jumping max/min values but it stil jumps around.
Any ideas? Any ideas on how to solve?
New to this forum and wondering if anybody can explain:
A have this old traditional car battery charger. Works fine but the build-in analog ammeter got stuck. 230V in and 12/24 V out.
Got the idea of digital replacement and fitted a digital voltmeter at the same time (to monitor battery and check behavior when charger is shut off). Voltmeter works as expected.
The ammeter is digital, connected to 12v pos & neg, to power it, and to each side of the shunt (200A, 75 mV) to measure amps. Terminals marked 5V, O, IN- and IN+.
Whenever power is on, no matter if the measuring wires are connected, the digits jumps about. All sorts of readings, even negative.
Conncting the measuring wires will change the jumping max/min values but it stil jumps around.
Any ideas? Any ideas on how to solve?