trinityamps.com

just received shipment of my 18W kit...got it with the VRM...but still undecided if i'm going to build that in yet...

before i start wiring, i was wondering if there is a way to tap off of the tranny to power a couple LED's to backlight the amp? if so, i want to make sure i can take that into account prior to laying everything out...

thanks!

Put the LEDs in parallel with the heater winding. Don't forget to use a current limiting resistor.


So you have two heater wires (the solid green ones). Attach one side of the LED to one green wire and the other leg of the LED is connected to a resistor which is in turn connected to the other green wire. For the resistor depending on what LED you use, 220R-10K should be good.

_________________
http://pdfelectronics.com

excellent...shouldn't be too hard to do then

will probably make a 'plug' to use...so the LED's can stay in the shell when i take the chasis out of the cab...

was thinking about this afterwards...its DC power going to the jewel isn't it? could i now just piggyback power off of the jewel?

if not...and i just tapped of heater wires (the green ones off of the tranny), if i ran a dozen or so LED's would a high valued resistor still be required?
i would assume, that there would be no issue just tapping in at the tag strip?

The jewel/indicator lamp runs off 120 volts AC so, no you can not.

Check out http://ledcalculator.net/. You can design your circuit and will look something like below. First one is for a single blue LED. Second is for 12 blue LEDs. I am still planning on doing this to my amp as well. Just haven't got around to it yet.

_________________
Les

http://www.soundclick.com/unimind

cool...thanks for that...i used this in my last amp...but used a 9V battery instead...
http://store.qkits.com/moreinfo.cfm/LDB1-HS3018AR

i hoped to either use this again, but tie it into the power supply to backlight...or...get a sheet of plexi glass and take 4 LED's and do a front panel a la H&K amps

It looks like that would work as is. Even though it says 12 volts it should work with 6. Just may not be as bright.

_________________
Les

http://www.soundclick.com/unimind

6V can be just as bright as 12V.
LEDs drop 1V-3V across them. The rest of the voltage gets dropped across the current limiting resistor.

_________________
http://pdfelectronics.com

What are you planning to backlight?

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

I had hoped to get a custom headshell that looks the same on the front as it does the back...open steel mesh...then i could put the leds in and see the glow thru the mesh

I was looking at this again and realized something. The heater tap off the transformer is AC not DC. So I think you have to rectify it before using it to power the LEDs.

_________________
Les

http://www.soundclick.com/unimind

i was thinking about it last night and was thinking the same thing...i thought it was AC...

which then confuses me...since you take the two green wires off the trany and hook them up to the heaters...whether black is black or black is red...there is no difference? my schematic shows one green wire hooking to the red...and the other to the black...

The voltage is AC yes but it's also 60Hz. The led is being switched on and off so fast at that frequency the human eye can't distinguish the two states.

_________________
http://pdfelectronics.com