I'm looking for a schematic that would show a 555 timer energising a relay for a period of two seconds every 10 seconds using a capacitor rated at 10 micorfarads. I'm aware of all the relevant pins on an IC 555 chip but could just do with some help locating a diagram of this... It would also be handy if one terminal of the relay coil is connected to 15v DC Thanks
T = 0.7 × (R1 + 2R2) × C1 and f= 1.4/(R1 + 2R2) × C1 T = time period in seconds (s) f = frequency in hertz (Hz) R1 = resistance in ohms (ohm) R2 = resistance in ohms (ohm) C1 = capacitance in farads (F) Mark time (output on): Tm = 0.7 × (R1 + R2) × C1 Space time (output off): Ts = 0.7 × R2 × C1 Put in the capacitor values and play around with what resistances can give you those times. Diagrams of the circuit your looking for are on: http://www.kpsec.freeuk.com/555timer.htm#astable Look for the 555 Astable design and just above it on how to hook the relay up From what i remember the relay can switch absolutely anything its rated for as part of a seperate circuit.
http://www.electronic-circuits-diagrams.com/index.shtml will probably have something suitable. Used to have great fun at uni with 555 timers energizing a buzzer after a set time. We'd tape them to the underneath of someone's bed and set them to go off at 5am
