I got to the bottom of this fault.
The LM339 was saturated ,the VCC was 11 volts pin 11 was at 6 volts ,this is set by V Ref .As I thought it should have been half the VCC ,the 470uF capacitor connected to the VCC was leaking and pulling up the voltage.
I made a few changes to the circuit .
Added a Si diode the VCC circuit to raise it to 12 volts ,connected a 10M resistor between pins 10 & 13 on the LM 339.The two resistors that set the V Ref seemed a bit odd to me 47K & 51K ,I changed these to 56K & 47K beacause the VCC and V Ref did not track as the voltages drop as the batteries ran down.
Barry Wilkins
The LM339 was saturated ,the VCC was 11 volts pin 11 was at 6 volts ,this is set by V Ref .As I thought it should have been half the VCC ,the 470uF capacitor connected to the VCC was leaking and pulling up the voltage.
I made a few changes to the circuit .
Added a Si diode the VCC circuit to raise it to 12 volts ,connected a 10M resistor between pins 10 & 13 on the LM 339.The two resistors that set the V Ref seemed a bit odd to me 47K & 51K ,I changed these to 56K & 47K beacause the VCC and V Ref did not track as the voltages drop as the batteries ran down.
Barry Wilkins
Attached Files