Electronic Head or Tails Circuit


This is an electronic head or tails circuit ,that same really the head or tail playing very little head by following several steps.
-First of all,turn on switch, LED display show digit “0”.
-Secondly, press the button “rotate” then the coins computer will begin rotate, notice of LED1 will be light, wait until LED1 go out.
-Next, select switch S3 to guess “head” or “tail”.
-When guess, then press S4 to “Open”. This circuit to check, if you guess right the score will move up to No. 1 and again 1 step to step. If wrong, all your points accumulated will be lost.
Electronic Head or Tails Circuit

How it works
This circuit is all digital, no transistor. So easy to understand.
– In figure circuit, when turn on S1, IC1-LM7805 as 5V DC fixed voltage regulator to control voltage in level of 5 volts. And apply the power to all IC in this circuit.

-If we press S2, will has volt to charge C1 until state as “1” to IC2/1 and IC2/2 that are connected as the oscillator circuit to generate clock signal to IC3/1.

– Which is delay flip flop that connect the clock signal to the 2 divider circuit at pin 12 and feedback always to pin 13 of IC3/1.
-Then, C1 discharged fully down to “0” then IC2/1 and 2/2 will stop oscillation.
-Cause IC3/1 still display is pin 13 or pin 12 will has signal is “1” into pin 5 of IC3/2.
Choosing correct and wrong.
Assuming that the pin 12 is “1″, and We chose this way fit. cause pin 5 of IC3/2 is also “1” .

– But output of IC2/3 is “0” because connected as the inverter, cause pin 1 and pin 5 of IC4 ©©©© “0”. and when press S4 will makes pin 2 and pin 6 of IC4 is “1”.
-And the same time, pin 3 and pin 4 of IC4 will be also “1” .
-But through IC4/3 and IC4/4, which is connected also to the inverter, cause pin 10 and pin 11 is “0”. so no signal to reset IC5 and feedback to IC3/2.
-When we press S4 will cause pin 1 of IC3/2 is “1”, which 0-9 binary counter circuit.
-When IC5 get signal Clock then convert the binary signal into IC6 which is decoder IC to convert the signal to drive the 7 Segment LED, to show score.
– If wrong pin 5 of IC3/2 will be “0” while pins 8, 9 of IC2/3 will be also “0”, but pin10 of IC2/3 will be “1” cause pin 1, 5 of IC4 is “1”.
-When we press button “turn on” which will cause pin 2, 6 of IC4 is also “1”. Thus at pin 3, 4 of IC4, will be “0” but when through IC4/3 and IC4/4 will cause “1” to reset IC5, cause the output is “0” again.

The parts you need
IC1______LM7805__5V DC voltage regulator
IC2,IC4__CD4011__Quad 2-Input NOR Buffered B Series Gate
IC3______CD4013____CMOS DUAL D-TYPE FLIP-FLOP
IC5______MM74C93_____4-Bit Decade, Binary Counter
IC6______74C48___BCD-to-7 Segment Decoder


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