Flashing LED Lights Kit ML100
Beginner Skill Level Electronic Kits
Flashing LED lights electronic kit
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Flashing LED Lights
The flashing LED light circuit and kit shown above is known as an astable multi-vibrator. The circuit diagram of the Flashing Lights is shown
above. It consists of two transistors (TR1 & TR2), two electrolytic capacitors (C1 & C2), two lights or LEDs (L1 & L2), and four resistors (R1 to R4).
When a 9V battery is connected to the circuit the transistors TR1 and TR2 start to switch on and off in turn causing the LEDs to emit pulses of light.
The circuit oscillates and the LED lights begin blinking alternately and continuously.
To understand how the circuit oscillates we must consider the voltage variations across the capacitors C1 and C2. Consider the situation just before TR1
switches on. C1 has already charged up to 7 volts through R1. C2 is charging through R3 and when the voltage reaches 0.6 volts TR1 turns on. The collector of TR1 and the positive end of C1 are
pulled down to 0 volts which forces the negative end of C1 to -7 volts. This has the immediate effect of switching TR2 off. C1, however, is also connected to +9 volts through R2 and this causes
C1 to charge in the opposite direction. The voltage at the negative end of C1 (the base of TR2) therefore starts to fall from -7 volts and rises towards 9 volts. However as soon as the voltage
reaches 0.6 volts TR2 switches on and a charged-up C2 turns TR1 off. C2 now charges in the opposite direction through R3. The voltage at the negative end of C2 rises towards 9 volts and
turns TR1 on when it reaches 0.6 volts. The circuit is now back in its initial state and the cycle repeats itself.
The combination of C1 and R2 determines the time TR2 is switched off, and similarly C2 and R3 determine the time TR1 is off. The values used in the
circuit give an on-time (and off-time) of about 1/3 second. This is a blinking rate of 3 flashes per second. Flashing LED light kit assembly is required.
Flashing LED Lights Kit Specifications
- Flashing LED lights PCB dimensions 2" x 2" (5.08cm x 5.08cm)
- Power supply 9V battery (not included)
- Download and print
FACES to cut out and fit over the flashing LED lights kit!
- Flashing LED lights kit assembly is required.
- A really great educational gift !
Flashing LED Lights Price
Flashing LED lights electronic kit ML100 is economically priced at:
Only $ 8.49 + shipping!
Mail or FAX Order Flashing LED Lights Electronic Kit ML100
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