Posted on Mar 18, 2013

The circuit consists of two building blocks. The first is a square wave oscillator made up of two transistors in a multivibrator arrangement and the second is a CD 4017 decade counter IC. The multivibrator contains two extra components to speed up the waveform and make it acceptable for all brands of 4017`s. Unless the output has a very fast rise and fall characteristic, some 4017`s fail to operate properly. They either do not work at all or jump two or three outputs, losing the scanning effect.

Click here to download the full size of the above Circuit.

The two speed-up components are the signal diode and 39k resistor and are essential for reliable operation. The output of the multivibrator feeds into the CLOCK INPUT of the chip. From there is goes to a complex counting circuit inside the 4017. The circ

Leave Comment

characters left:

New Circuits



Popular Circuits

Digital-Output Sensor Simplifies Temperature Acquisition
Electronic potentiometer schematic
Long-Interval Programmable Timer
5v Powered Charge Pump Battery Charger
help diagnose stator
hv dc dc converter
Two-Position Dimmer
IR Widget
lf286 Linux USB LCD display with watchdog and buttons
Current negative feedback electronic frequency power amplifier circuit