On the face of it, that sounds good to me - you are kind of using the driver as the control system - but this will probably increase the fun of running the loco - and heck, we do it with the steam loco's. Would still have a play with the arrangement on the bench if there is even the slightest chance that you may be wasting effort by setting the whole thing up in the loco. One slight thing to watch for, I think there is some issue with disconnecting the battery from the alternator whilst the engine/alternator set is running - possibly could cause damage to its voltage regulator (as you switch from batterys to dummy load there will be an instantanous change in current, this will cause a voltage spike due to the inductance of your wiring and the alternator - this spike could easily kill anything silicon based, such as the voltage regulator - your speed controller should be safe, as you will have switched this out of the circuit). Switching off the excitation current into the alternator (with a freewheel diode on the alternator side of the switch) is a safe way of reducing the alternator output current to zero, whilst you change from battery to dummy load or visa versa, before you switch the excitation current back on again - but this is again getting more complex. There may be a simpler way around this though, or something I'm missing. Yours, Rich. On Wed, 30 Mar 2005, Peter Sheppard wrote: > Firstly, apologies for the big snips - the mailing list only allows 20 lines > of > text carried forward! > > OK, I was trying to make this a KISS project (keep it sweet and simple!) > MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.