Coasty

I have an older Ace "FFC", or Fast Field Charger that has outputs for both TX and RX - operates off a 12V field battery.

A friend gave this to me to fix - it had not worked in some time.

I seem to have it working - but it runs fairly hot during operation. I see that the current regulator transistors use the aluminum front panel as a heat sink - so I expect that it can be expected to get warm, but was surprised to see that it gets almost too hot to touch for any period of time. I noticed that the screen lettering on/near the heat sink area was worn - perhaps from the heat of using it in the past.

Anyone used a similar charger before? Did they get warm/hot under normal operation? Do the red LEDs flash when the battery is fully charged. The components I fixed / replaced really have nothing to do with the charge and regulator portions of the circuit. It seems to be producing the proper voltages and current to the battery.

Attached to the RX battery lead is what appears to be a transistor with separate leads connecting it to the PC board. Perhaps this is a battery temp sensor? If how is it used?

This unit is in a black plastic box - palm size and has an aluminum front panel with black lettering.

Thanks

ballgunner

My Feedback: (1)

Unless you are into antiquing the repair of old style chargers can be an exercise in futility. The cost of replacing ruined batteries can far exceed the cost of modern charging equipment. Heat is the major cause of loss of useful battery life. Unless this oldie has provision for peak detection shutoff you should mount it on a concrete block to prevent fires.

Coasty

I hear you...good point.

The batteries remained cool though - no sign of them getting even slightly warm, and the current / voltage the thing was supplying was within specs. The only heat was generated by the regulators.