If the bridge rectifier is wired immediately upstream of the coil, with the two ends of the coil connected to its + and - terminals, and its ~ terminals connected to the places where the coil wires were, there is no need to isolate the e-unit frame, and the switch continues to work.
Bob Nelson
trains4fun Put in the full wave bridge, silent. rated at 400V 1.5 amp, $2.99. There is a barely audible buzz at full voltage. Can only be heard when everything is silent. Fixed the problem for me.
Put in the full wave bridge, silent. rated at 400V 1.5 amp, $2.99. There is a barely audible buzz at full voltage. Can only be heard when everything is silent. Fixed the problem for me.
I assume you did as ADCX Rob mentioned, and that is fully isolated your e-unit coil from the system, or more specifically from using the frame ground. That implies you no longer have a working e-unit switch, correct? Did you just leave the e-unit coil permanently wired into the circuit, or did you add another switch somewhere?
Did you need to use the capacitor?
I would try the bridge rectifier without the capacitor first. That might be quiet enough for you and will avoid the extra coil heat that will come from adding the capacitor.
Gee, I always loved the sound of the E-unit, struck me in the same way as a double drum roll before a military band starts a selection, a little taste of something really good that was coming.
To each his own, I suppose.
Or does it really need a full wave bridge isolating the e unit coil completely isolating it from the rest of th system?
Yep, that'll silence the buzz. This also works with any buzzing accessory where buzzing is not needed.
Thanks for the information about the full wave bridge, it makes sense. In fact I bought some just in case when I bought the other supplies.
For the other question, the configuration only ran the coil.
I think I just re-discovered the stand alone horn relay. Resistor of the right value, capacitor and a diode or 2 in the right configuration and you induce DC current on the track..
I am not trying to make all my E-units noisless. A little buzzing is OK. The worst offender is in the F unit. The shell acts as an echo chamber and it is almost as loud as the horn.
The rest of your locomotive is powered directly from the pickup, and not from the e-unit coil's terminal, right?
By blocking half of the AC sine wave to the E-Unit with one diode, & referenced to chassis ground, you have introduced a half wave DC bias in the opposite direction to the chassis... so yes, it really needs a full wave bridge isolating the e unit coil completely from the rest of the system.
Rob
I tried the diode/capacitor fix listed in this old noisy E unit discussion.
It does quiet the E unit perfectly, but the problem is it fires off the horn or whistle continuosly.
CW80 transformer.
Any Ideas on what could be wrong? Capacitor neg to ground, diode cathode toward E unite, capacitor positive connected to E unit after the diode. Or does this just not work with horns and whistles in the mix.
Any success stories?
I have a 2065 with an original E unit that makes 0 noise, but all my others make noise of some kind and I would like to quiet them if possible.
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