It does; but his is 10 Ohms instead of 1k Ohms.@ Sgt: Good point about the 1K resistor and the wiper pot for circuit 2. How come Bill's circuit does not use one?
You could use a 2N2222/PN2222 if you wished. Base current would need to be 40mA to saturate the transistor. The maximum Vout of a 555 timer is Vcc-1.3 even lightly loaded due to the Darlington configuration. Vbe for a 2n/pn2222 will be around 0.8-0.9v when Ic=400mA. So:Q: I am using a regulated 12V source to controll a 12VDC motor rated at 400mA. Do I need a MOSFET or is a transistor OK?
If your circuit is battery powered, a capacitor will extend the battery life considerably. If powered by a supply, the 555 timer requires a minimum of an 0.1uF/100nF and a 1.0uF cap across it's Vcc/GND pins for reliable operation. The motor being on the same supply increases that requirement.Q: C2, 220uF... can you explain this cap as I have not seen this in other circuits. Circuit 1 that I posted shows a 1uF cap from +12V to GND. Are they acting in the same capacity? I ask because a 220uF 16V cap starts to take up some real estate!
by Jake Hertz
by Jake Hertz
by Jake Hertz
by Duane Benson