AC / DC power module typical application circuit
Input voltage range: 85VAC ~ 264 VAC external capacitor, recommended value 6.8uF / 400V output filter capacitor C2 is electrolytic capacitors. Ceramic capacitors C1, C3 can be used film capacitors or electrolytic capacitors.Cycling is our usual means of transport, if accompanied by a bicycle speedometer, you will be able to master cycling speed, especially for cyclists, the peacetime training, a reasonable allocation of the way the speed, rhythm master speed, is a good method,
Cicycle speedometer circuit..below. The speedometer use bike rideline speed is proportional to the rotation of the wheel, the wheel rotation frequency linear convert the DC
voltage, and remove it from power ripple voltagevoltmeter displays the voltage value corresponding speed riding.When riding in the infrared light detector per revolution of the wheel when moving hair a week, the first pulse, the crystal tube VT2 conduction pulse to produce a next-hopsingle trigger-based integrated circuit consisting of 555
-shot. Riding faster time infrared light pulses emitted by the two detectors shortened, increasing the number of one-shot circuit output is high, the
average value of the DC voltmeter indication. Meter scale units to speed in km / h, the number of bicycle wheel rotation can be calculated based on the wheel perimeter
derived, currently used bicycle 71cm (28in), 66cm (26in), 60cm (24in), 50cm (20in) 4 class , given the scale 4 that
can be. 28in bike to calculate, when as 40km / h speed line Chi, the wheels turning about 2.5 times / s. Forgiving one-shot circuit RP1 timing resistor and capacitor
values ??can be used iookfl c2 and o. 47vF.
In the bike speedometer, the infrared light detector can be used in any infrared tube, LED and VT1 installed in specialized stent, the stent with a thin metal
plate since the sectional shape may refer to lock structure and mount the bike wheel spokes upload a shelter materials, so that each wheel one revolution, the red
light detector is shielded from the outside once. NPN transistor with a silicon transistor VT2 9014, about 120 betas election. Time-base integrated circuit NE555.
Potentiometer RP1, RP2. Both with WH7 type trimmer potentiometers, remaining resistors are used RTX type 1 / 8W carbon film resistors. Header with 91C2 type.
The rest capacitors are used CJ11 metallized paper dielectric capacitors.