Solid State Guitar Amp Forum | DIY Guitar Amplifiers

Solid State Amplifiers => Amplifier Discussion => Topic started by: bazmusicman on January 08, 2016, 06:30:35 AM

Title: LIGHT BULB LIMITER
Post by: bazmusicman on January 08, 2016, 06:30:35 AM
As I am about to embark on making one of these,  on the first diagram on how to make one, it only shows 2 wires. Shouldn't there be an earth wire if working on items that need to be grounded, or is it because with the bulb sucking the load we are only talking low voltage here?

Regards,
Baz.
Title: Re: LIGHT BULB LIMITER
Post by: Enzo on January 08, 2016, 06:53:08 AM
The ground wire is beside the active circuit.  If you want to add a ground wire to your setup, go ahead.  It has nothing to do with voltages.
Title: Re: LIGHT BULB LIMITER
Post by: bazmusicman on January 08, 2016, 09:01:50 AM
Thank you Enzo,   
Its dawned on me that this is just a normal 2 wire light bulb setup!!
They say that there is no such thing as a dumb question, but that one must have been pretty close!!!!

Regards,
Baz.

PS  In my defense;  in England now all domestic electrical equipment has to be earthed.
Title: Re: LIGHT BULB LIMITER
Post by: UsableThought on January 08, 2016, 11:12:28 AM
Quote from: bazmusicman on January 08, 2016, 06:30:35 AMAs I am about to embark on making one of these,  on the first diagram on how to make one, it only shows 2 wires. Shouldn't there be an earth wire

If by "first diagram" you mean the diagram in post #1 of the stickied thread on this forum (http://www.ssguitar.com/index.php?topic=2093.msg13855#msg13855), it is actually two diagrams & the lower of the two does show earthing.

This is not trivial by any means nor does it seem wise to say it is just a light bulb circuit. Mains voltage and domestic appliances, including lamps, have certainly killed far more people than the high voltage inside a tube guitar amp.
Title: Re: LIGHT BULB LIMITER
Post by: Enzo on January 08, 2016, 03:01:50 PM
Asking about the bulb thingie tells me you are going to be working inside an amp.  SO that means we need to be cautious all around.  be aware of all voltages mains or otherwise.  We want everyone to be safe.
Title: Re: LIGHT BULB LIMITER
Post by: bazmusicman on January 08, 2016, 06:31:49 PM
Thank you Usable Thought,
Yes I did mean the top diagram of the two in the stickied thread.
I was not implying that it was trivial by saying it is just a light bulb circuit, I was referring to the way a ceiling light is wired. As you say mains voltage, lamps, appliances etc are dangerous, this is why I queried a no earth wire.

Thank you Enzo,
I have worked on tube amps and I am still learning but of cause safety is the number one priority,  I liked the idea of the light bulb limiter for that very reason.   
I am at the moment repairing a solid state amp with the help of you all on this brilliant site.
Once again thank you all.
Regards,
Baz.