Live Wire Scanner. Design Trick 11



Try this single IC circuit for Non contact detection of current in live wires. It can detect the presence of AC from a distance of 30cm or more without touching the bare points of live wire. It is ideal to detect cable break, switch board faults, earth leakage etc. The circuit detects the e.m.f (called AC hum) present around the live wire when the electricity passes. Only a single IC CD4033 can do the trick.
Continue reading “Live Wire Scanner. Design Trick 11”

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.
Continue reading “CD 4017 Johnson counter – Design Trick 3”

Design Your Circuit. Part VIII – CD 4033 Counter


Again another Johnson counter IC for digital display. CD4033 is the 5 stage Johnson Decade counter with Decoder. The output decoder converts the Johnson code to a Seven segment decoded output which can drive LED or 7 segment display in numerical values. This IC is widely used in 7 Segment decimal display circuits, Frequency division 7 segment displays, Clocks, Timers etc. Let us see it’s is working and the circuits.

Continue reading “Design Your Circuit. Part VIII – CD 4033 Counter”

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.

Continue reading “Design Your Circuit. Part VI – IC 4017 Circuits”