Help Needed With NPN Transistor

Thread Starter

MrScott

Joined Aug 20, 2013
14
Or, are these new LED's bright enough if you would hook them up using only the 12 volt supply and 1k current limiting resistor?
To test the LED's you could use the circuit you posted above on the left provided you add a resistor connected to the base, other end to 12 volts. 10k would work.
I don't quite understand what you're asking.

The LEDs will be powered by a 12v supply with a 1k ohm limiting resistor.
 

tubeguy

Joined Nov 3, 2012
1,157
It's likely that the points you have labeled GND 1 and GND 2 are actually current sink outputs. They are probably NPN transistors,

But, they are not actual GND connections. Are you comfortable with locating the circuit GND on the gaming console ?
 

Thread Starter

MrScott

Joined Aug 20, 2013
14
It's likely that the points you have labeled GND 1 and GND 2 are actually current sink outputs. They are probably NPN transistors,

But, they are not actual GND connections. Are you comfortable with locating the circuit GND on the gaming console ?

I would have also said that they were NPN transistors, I just labeled them as GND so that it could be differentiated from the 2v.


I can locate the 0v GND on the console, yes.
 

tubeguy

Joined Nov 3, 2012
1,157
I would have also said that they were NPN transistors, I just labeled them as GND so that it could be differentiated from the 2v.

I can locate the 0v GND on the console, yes.
Current sinks should work as before. The new supply needs to be referenced to the same GND as the console.
Before connecting as below please post a drawing to make sure we are on the same page. Or you may damage the console.

Connect the ground of the new 12 volt LED power supply to the console GND. Then, connect the new LED with the 1K series resistor between the 12V+ and one of the current sink connections.

If all is as described it should work.
 

Thread Starter

MrScott

Joined Aug 20, 2013
14
Current sinks should work as before. The new supply needs to be referenced to the same GND as the console.
Before connecting as below please post a drawing to make sure we are on the same page. Or you may damage the console.

Connect the ground of the new 12 volt LED power supply to the console GND. Then, connect the new LED with the 1K series resistor between the 12V+ and one of the current sink connections.

If all is as described it should work.

Thank you so much, that makes complete sense.
I will connect a test up and give it a go but I can't think why it wouldn't work.
I have several of the LED boards for the console so I will write back if I blow one up.

Thanks again.
 
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