Dr G, and all
I found an IC that will connect to 120 volt mains and drive a LED
directly without many other components. Check out:
http://www.irf.com/product-info/datasheets/data/irs2540pbf.pdf
Not a bad deal for $1.50.
Have fun
bill
Trade Wind in WV
>>I also have a burning interest in LEDs. Since they are so sensitive to
>>over voltage could you send me information (part number?) on what you
>>use to keep the voltage correct. I am concerned as charging voltages can
>>be as high as 14 volts. Are you using a SCR or something else to fine
>>tune the voltage?
>>
>>You may want to answer off list as this is only marginal to Airstream.
>>
>>
>A simple series resistor is all that's needed. Figure its value from the
>difference between the supply voltage and the operating forward voltage,
>divided by the desired current through the LED. Say 14 volt supply, 2.5
>volt LED drop, desired 20 milliamps, the standard test current.
>(14 - 2.5) / .02 = 575 ohms. Use the standard value 560 ohms.
>Dissipates .236 watt, best to use a 1/2 watt rated resistor. The
>resistor will limit the current and the diode itself will limit the
>voltage.