How to build Photo Timer Circuit

Circuit diagram

5a彩票手机下载time is set by potentiometer r2 which provides a range or 1 sec. to 100 seconds with timing capacitor c1 of 100uf. the output at pin 3 is normally low and the relay is held off. a momentary push on switch s1 energies the relay which is held closed for a time 1.1 x (r1+r2). c1 and then released. the exact length of the timing interval will depend on the actual capacitance of c1. most electrolytic capacitors are rated on the basis of minimum guaranteed value and the actual value may be higher. the circuit should be calibrated for various positions of the control knob of r2 after the timing capacitor has had a chance to age. once the capacitor has reached its stable value, the timings provided should be well within the photographic requirements.

C1 - 100uF, 25V electrolytic
C2 - 0.01uF, disc ceramic
D1, D2 - DR50 or 1N4001
R!,R2 - 10K ohms, ¼ watts
R3 - 1 M ohms, potentiometer
RLY1 - 12V, DC relay, operating current less than 200mA
S1 - Push-to-on switch
U1 - NE555 timer IC
5a彩票手机下载 P1 & P2 are for exposure lamp ckt.

Download this project in doc format

Author: Ravi Sumithraarachchi
Email: ravi@ualink.lk
Website: http://www.electronics-lab.com

Similar diagrams

We are not responsible for any injuries or damage caused by information from this website! Working with electricity is dangerous for your life, especially diagrams related to high voltage! We do not guarantee success in building devices using our diagrams! They are not tested by us. For questions about diagrams use author info below diagram or our contact page. Thank you!
2元中国福利彩票的买法 2元买彩票选几个数字 2元就可以打1毛的斗地主棋牌 2元中国福利彩票怎么看 2元就可以打1毛的炸金花棋牌 2元彩票刮刮乐 2元彩是值得您信赖的 2元彩票 2元彩不错 2元彩票双色球走势图双色球