Radiation Sensor. Simple Design 27


This circuit tells you how much radiation is coming from electric devices. It picks up the AC hum from the surroundings of electric equipment and electric wiring and blinks the LED to show the radiation level. You can also use this to assess the safe distance from Computer radiation.
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AC Scanner. Simple Design 11

With a single IC you can make a simple Non Contact AC tester. Just move in front of an AC wire, switch board etc that carrying AC, the LEDs in the circuit runs indicating the presence of AC in the wire.
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CD 4017 Johnson counter – Design Trick 3

CD 4017 is the Johnson Decade counter IC used in Running light and Message display applications. It is a 5 stage divide by 10 counter with decoded outputs and a carry out bit. The counters inside the IC advances with each positive edge triggered pulse when the clock enable pin 13 is held low. Each decoded output is normally low and turns high with its time slot based on the input pulses. Each output remains high for a complete clock cycle. The carry out signal completes one full cycle for every 10/8clock input cycles and is used as ripple carry signal to the succeeding stages. The input signal can be from an oscillator such as an Astable multivibrator using IC555.
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Design Your Circuit. Part VI – IC 4017 Circuits

IC 4017 is the 5 stage Johnson Decade counter IC widely used in chaser lighting circuits. It takes the clock pulses from the Clock input and makes one of the ten outputs On in sequence each time a Clock pulse arrives. A Johnson counter, also called Walking ring counter is the modified Ring counter in which the last stage is Inverted and fed back as the input to the first stage. It is a Decade counter since the counting is in Decimal digits and not in Binary. See the working details of CD 4017 and the Circuits.

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