1 Topic by KuifjePDX (edited by KuifjePDX July 23, 2009 1:46 pm)

  • From: Somewhere in space-time.
  • Registered: July 31, 2008
  • Posts: 134

Topic: Allesetende LED

I'm working on the design for a small driver station and was looking for something to show that power is available at the terminals. Since the power will come from a variable power supply between 12 and 20 Volts DC the LED would need some sort of limiter to not overpower it. Rather than using a voltage regulator with associated resistors and capacitors I found this little circuit at Circuits Online that should work with just one transistor. It may be possible to drop the diode if the supply voltage is DC only.

http://lh4.ggpht.com/_6Ftqp6rtQJQ/SmiP1ru92KI/AAAAAAAAAC8/hCoAy8Q0SqQ/Allesetende%20LED.gif
The FET acts as a constant current source when Gate and Source are connected.
The supply voltage can range between 4 and 30 Volts while the current through the LED will remain around 15 mA.
When used with an AC supply the LED light will be dimmer.

Once I am done building the driver station I will post pictures and schematics.

George

--
"Get the shotgun, Martha. The herd needs a thinnin'." - Bucky Katt
  • wb0s
  • wb0s
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  • From: Vancouver, Washington
  • Registered: June 16, 2008
  • Posts: 5,576

Re: Allesetende LED

Way cool stuff George!!!

So if I'm reading this correctly, the LED will be illuminated at the driver's station when power is on to the track, whether a controller is hooked up or not?

------------------------Bill

wb0s's Website

3 Reply by KuifjePDX (edited by KuifjePDX July 23, 2009 2:20 pm)

  • From: Somewhere in space-time.
  • Registered: July 31, 2008
  • Posts: 134

Re: Allesetende LED

Technically, it will show that the driver station has power (whether the controller is hooked up or not), power to the track must go through the controller and is only applied once you pull the trigger. I guess you could connect it to the black lead of the controller to see if your controller sends power to the track, but that may interfere with the variable braking action in the controller/driver station. I haven't thought that one through yet.

George

--
"Get the shotgun, Martha. The herd needs a thinnin'." - Bucky Katt