I have finished most of a hypex build and have tested the voltage outputs of the ST power supply to drive two ST180 amplifier modules. All + and - voltages are correct on my multimeter. Yippie! How do I run an LED off of the ST power supply LED +/-. I want to use an LED on the front panel to show the amp is on. I installed a green LED unit from radio schack, but when I hook the leads up to the ST power supply LED + and - it does not illuminate. Any ideas? What is the proper voltage out of the ST power supply LED section?
Probably. Do you know the voltage at the LED +/- connection? If yes, divide that voltage by 0.01. That will be be resistance in ohms to use in series with the LED.
That allows ~10mA thru the LED. Too bright use a little higher resistance; too dim use a little lower resistance.
That allows ~10mA thru the LED. Too bright use a little higher resistance; too dim use a little lower resistance.
I am getting a reading 24 volts from the LED + out on the power supply module. I am surprised it is that high. I found an online LED calculator, and looks like I will need a 1.2K ohm resistor in series with the green, pre-wired Radio Shack LED unit.
Since I ran 24 volts into the first LED i had installed on the chassis panel, I imagine it is toast? Despite the LED misfire, the rest of the Hypex amp is up and running and playing nice music.
Since I ran 24 volts into the first LED i had installed on the chassis panel, I imagine it is toast? Despite the LED misfire, the rest of the Hypex amp is up and running and playing nice music.
What is the part number for that pre-wired radio Shack LED? Some (most?) of those are made to easily connect to a particular voltage, with the series resistor built in. If that's the case here, the 1.2k might work if it drops ~12V, leaving 12V for the RS LED. Kind of big "might", though.
Here is the Radio Shack LED:
Model 276-271
Product Type >7 mm lens
Enclosure Color GREEN
The unit has a black wire on one side and red on the other. The black wire does have an area in it that looks like it may house an LED, so I was presuming that was the case and that it would work with the Hypex. Maybe it is for 12 volt vs. 24. The literature on line says nothing about voltage.
Model 276-271
Product Type >7 mm lens
Enclosure Color GREEN
The unit has a black wire on one side and red on the other. The black wire does have an area in it that looks like it may house an LED, so I was presuming that was the case and that it would work with the Hypex. Maybe it is for 12 volt vs. 24. The literature on line says nothing about voltage.
So at 24 volts it is getting double the voltage needed. So if I drop a 680 ohm resistor in series bofore the LED maybe that will work to drop the voltage to 12?
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