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Old 09-01-14, 00:26
Chris Suslowicz Chris Suslowicz is offline
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Join Date: May 2007
Location: England
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Originally Posted by Bob Carriere View Post
Need to consult the schematics.....

Bruce on a regular power supply it seems to me that the only connection to the control box(es) is with the long twelve pin cable coming from the radio unit.

The regular PS has a 6 pin connector that is the power IN from the batt. or CPP-2......

Why would the 110v. PS send power to the control box(es)

Bob C
Okay, to the first question: audio and a buzzer call are fed through the power supply for tank use - where the supply unit is fed via the turret junction box and the rotary base junction into the tank hull wiring loom.

Second question: the 6-pin power input plug is fully wired, and has 2 x 12 volt inputs (one is for the valve heaters and relay supply, the other is for the dynamotor) so that it can be split (if required) across a 24 volt 3-wire system as well as being used on 12 volts. The other two wires are labelled "Speech" and "Signal". The Speech is for the tank intercom, and the Signal is for a buzzer on the driver intercom box (Junction, Distribution, No. 1 or No.3) operated by the "Call Commander" pushbutton on that box.

Third question: this particular supply unit does not feed power to the 6-pin input connector. (At least, I don't think it does as that might cause real trouble if you have an external 12V feed on there as well.)


Those supply units are a) scarce and b) electrically fragile. If the heater-to-cathode insulation fails on any of the 6X5 rectifier valves it can cause complete failure of the unit, effectively putting it beyond repair - all the transformer and smoothing choke parts are in a big, sealed, bitumen-filled canister which is very difficult to fix.

Also, do not fit fuses larger than 250mA to the output circuits. If your set draws enough to blow those fuses then you have (probably) a leaky capacitor or HT short circuit problem.

If you need to run the AC supply on 50Hz instead of 60Hz, there are a couple of wiring changes in the filter circuitry that need to be made first. Refer to the working instructions book for this.

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