and an Electronics n00b i need some help i want to make a ltl test fan controller using a normal LM317 regulator for the fan and LM3914N bargraph display to show how much power does the regulator gives. i looked the Circuits at LM317 - http://www.cpemma.co.uk/reg.html LM3914N - http://www.cpemma.co.uk/bargraph.html and i would like to make a 7-12V regulator knowing that 317 can't give me a full 12V i'll have to use a DPDT switch to bypass the 317 when i need full power i would like to ask those who know Electronics better then me (which is any1) to help me find out all the values i need to use on the circuits to make a 7-12 regulator with 7-12V display. and make u simple circuit that even i can understand and make that combines all that i need ( regulator and display) plz help this ltl n00b
Sounds like you got everything you need on those two pages. Then get a SPDT switch (ON-OFF-ON) as shown in this page: http://www.kpsec.freeuk.com/components/switch.htm And connect side A to 12V, side B to "Var Out" on the controller, and COM to your fan (positive side). When you slide the switch to A, it will be full power, slide the switch to B, it will be controlled by the fan controller.
