Circuit diagrams and schematics - Electronic projects

This simple Linear circuit provides continuously variable regulated current (~25-400mA) from a 4-6 Volt source. I chose a linear design for simplicity, reliability, ease of repair, and to avoid switching EMI in my Cave Radios. The circuit requires only 0.2V headroom above the parallel LED Array voltage to provide regulation at maximum current. The headroom [...]

This is a Constant Current Source LED Driver, When the LED driver Upper-NPN is driven by a voltage thru 4.7K the LED lights up. Assume that the Lower-NPN at bottom is absent. The current via LED and NPN is limited by R. 20mA may be ok 15mA even better. Or LED blows even transistor goes. [...]

This is a constant current source using a FET. This is the most simple replacement to series resistor to limit current. The N-Channel FET BF256C can give 15mA current. Source:http://schematics.blogspot.com/2007/02/fet-current-source.html Thank you. Related Links More Circuit about Current Source More circuit about LED Display Basic Current Source By LM334 FET Current Source by BF256 current [...]