I have this old ('80's era?) simple, 2 button type diode, manual auto battery charger that was working fine, but then not so hot. It is supposed to be a 6/12 volt (there is a switch), 6 AMP charger.
I tested the voltage output and saw 11.6VDC, so I knew something was wrong. I opened it up and there was a lot of rust inside. The most rusty section was the plate that had a couple of button diodes attached to it.
Before I investigated everything, I jumped right in and I assumed that a diode was bad and replaced the plate with a silicon bridge rectifier rated with the same voltage and amperage. I just used the + and not the - connection, since that was connected to the center tap.
Same results, exactly 11.6VDC output with a recently calibrated voltmeter.
This thing is about as simple as it gets. Here is a similar diagram of the circuit that is in it: www.circuitstoday.com/simple-battery-charger-circuit except there is no cap.
When the switch is on 6 volts, the output is 7.6VDC volts with no load and I think that is right.
But when the switch is on 12 volts, the reading is 11.6 VDC and inside 26VAC between the hot and neutral on the transformer outputs and 13VAC from the hot to the center tap. That doesn't seem high enough to me, so when the voltage is rectified and voltage loss is considered, it drops below the required amount to charge a battery.
I tested the voltage output and saw 11.6VDC, so I knew something was wrong. I opened it up and there was a lot of rust inside. The most rusty section was the plate that had a couple of button diodes attached to it.
Before I investigated everything, I jumped right in and I assumed that a diode was bad and replaced the plate with a silicon bridge rectifier rated with the same voltage and amperage. I just used the + and not the - connection, since that was connected to the center tap.
Same results, exactly 11.6VDC output with a recently calibrated voltmeter.
This thing is about as simple as it gets. Here is a similar diagram of the circuit that is in it: www.circuitstoday.com/simple-battery-charger-circuit except there is no cap.
When the switch is on 6 volts, the output is 7.6VDC volts with no load and I think that is right.
But when the switch is on 12 volts, the reading is 11.6 VDC and inside 26VAC between the hot and neutral on the transformer outputs and 13VAC from the hot to the center tap. That doesn't seem high enough to me, so when the voltage is rectified and voltage loss is considered, it drops below the required amount to charge a battery.
