Chore Horse Wiring Diagram

[stephen crowhurst]

Hello, dose anyone have a wiring diagram for the generator of a war time Charging Set 300 Watt Mk1. 15 Volts. Mod. No CHI-395-5. Mine was made by Outboard Marine & Manufacturing Company, Canada. Unfortunately when I got it the wiring had been played around with and some wires left dangling in mid air.
Thanks Stephen.

[Chris Suslowicz]

They're in the WS19 archive - Instruction book & repair parts list, First Echelon Work, etc. I'll have a look...

Doc 1803 is the user handbook and contains the circuit diagram, but is a Truly Appalling scan.

Doc 1598 for the post-WW2 BSA equivalent is a much better bet and a lot easier to read. They're the same basic machine.

Chris.

[stephen crowhurst]

Hello Chris thanks for the diagrams,
they shows four capacitors that do not appear in my chore horse, where they a later edition? I know the Amp meter is wrong but the rest seem original.
Cheers Stephen

[Chris Suslowicz]

Originally Posted by stephen crowhurst

Hello Chris thanks for the diagrams,
they shows four capacitors that do not appear in my chore horse, where they a later edition? I know the Amp meter is wrong but the rest seem original.
Cheers Stephen

Yes, the Mk.1 Chore Horse had no interference suppression on the generator output - I suspect it was only intended for 'stand alone' battery charging and not float charging of the radio batteries.

So the 4 capacitors (two across the brushes and two in the control box) and the choke in the control box (which, to quote Henry Reed: "in your case you have not got") were a later British modification to reduce interference (which apart from being an irritation to the radio operator would also be detectable by the enemy and give your position away).

The Mk.1 is something of a Brute Force device.

Best regards,
Chris.

[stephen crowhurst]

Thanks Chris, will strip it down and see what is still serviceable.
Cheers Stephen

[Bruce Parker (RIP)]

Chris, as always, your input is well thought out, accurate and...well...bloody bang on. Thanks...

Originally Posted by Chris Suslowicz

Yes, the Mk.1 Chore Horse had no interference suppression on the generator output - I suspect it was only intended for 'stand alone' battery charging and not float charging of the radio batteries.

So the 4 capacitors (two across the brushes and two in the control box) and the choke in the control box (which, to quote Henry Reed: "in your case you have not got") were a later British modification to reduce interference (which apart from being an irritation to the radio operator would also be detectable by the enemy and give your position away).

The Mk.1 is something of a Brute Force device.

Best regards,
Chris.

[charlie fitton]

"The Mk.1 is something of a Brute Force device."


But it is a chore horse and therefore always beautiful....

[Mike K]

I bought a NOS Outboard marine horse years ago. in the shipping crate was all of the bits/ancillaries , canvas cover, tools and spares .Pics

http://hmvf.co.uk/topic/27027-choreh...comment-328071

http://hmvf.co.uk/topic/27027-choreh...ge/2/#comments

[Chris Suslowicz]

Originally Posted by stephen crowhurst

Thanks Chris, will strip it down and see what is still serviceable.
Cheers Stephen

OK, there will be three wires coming out of the generator (the earth goes to the casing/frame)

1) Generator output +ve which connects to the +ve terminal on the ammeter.
2) Shunt (run winding) field coil +ve which connects to the rheostat end point.
3) Series (starter winding) field coil which connects to the Start button.

The wiper (moving contact) on the rheostat is connected to earth.
The Generator Output winding is a thick wire that connects to the +ve brushes.
The Series field winding is also a thick wire but does not go to the brushes.

Best regards,
Chris.

[stephen crowhurst]

Thanks Chris, the wire from the starter winding that connects to the Start button was one of the wires dissed off when I got the chore horse.
I take it that the rheostat connects to earth through its body too the casing?
Cheers Stephen

[Chris Suslowicz]

Originally Posted by stephen crowhurst

Thanks Chris, the wire from the starter winding that connects to the Start button was one of the wires dissed off when I got the chore horse.
I take it that the rheostat connects to earth through its body too the casing?
Cheers Stephen

Correct. The shunt field winding connects to the end of the resistance track, and the wiper arm is earthed to the casing. The resistance then controls the current through the field winding and that determines the strength of the magnetic field and hence the generator output voltage.

The start button connects a series field winding between the positive battery terminal and the positive brushes on the armature. That turns the generator into an electric motor to crank the engine when the button is pressed. (If the battery can't supply enough current to turn the engine over you have to resort to the cord and pulley method.)

Best regards,
Chris.

[stephen crowhurst]

Thanks Chris, I take it that the Amp meter should be 30A each way on the chore horse, that's all I can see in every picture I can find.
Cheers Stephen,

[Chris Suslowicz]

Originally Posted by stephen crowhurst

Thanks Chris, I take it that the Amp meter should be 30A each way on the chore horse, that's all I can see in every picture I can find.
Cheers Stephen,

The BSA charging set uses a Lucas 30-0-30 Amp 1.5 inch diameter meter, I suspect the original is very similar. (The generator is rated at 20 Amps output.)

Doc 299 in the 19 set group archive is a post-WW2 chore horse manual from "Threestokes" (Stokes, Stokes & Stokes Ltd.) which goes into a fair amount of detail on dismantling and reassembly of the unit, plus operation, parts lists, etc.

Best,
Chris.

[stephen crowhurst]

Thanks Chris for all your help, I will see if I can find a suitable Amp meter.

Cheers Stephen