Monostable Multivibrator - The schematic for a monostable multivibrator is shown in figure 3-11. Like the astable multivibrator, one transistor conducts and the other cuts off when the circuit is energized. __ Integrated Publishing, Inc. On/Off Flip/Flop Circuit with Automatic Timeout - This circuit is ideal when a device needs to be turned on and off with a single pushbutton switch, but also needs to turn itself off after some period of time. With the components shown, the output will stay on for only about 20 seconds. . . Circuit by Dave Johnson P.E.-May, 2012
One Shot (D-Flip/Flop) Circuit - Yes you can use cheap D flip/flop logic circuits as nice one-shot pulse generators. This schematic shows how the popular CD4013 and the CD74HC74 can be used to generate pulses ranging from nanoseconds to seconds. . . Circuit by David A. Johnson P.E.-June, 2000
Oneshot & Latch Pushbutton - This circuit uses a single IC to convert a noisy pushbutton switch signal into a clean pulse or a sustained push on-push off signal. It can operate from 3v to 18v . . . Hobby Circuit designed by David Johnson P.E.-March, 2002
Precision Missing-Edge Detector Also Correct - 10/26/95 EDN-Design Ideas - Unlike a typical missing-edge detector constructed from a retriggerable, monostable multivibrator (one-shot], the circuit in Fig 1 is programmable and accurate. Also, in the event of a missing-edge condition, the circuit generates a precision correction signal Design by Paul Sofianos, Motorola, Chandler, AZ
Pulse Period to Voltage Converter - This is a test circuit converts a square wave input signal into a voltage. But, the voltage produced is proportional to the time between edges (period) of the signal, not the frequency. The range is from 100uS to to 10mS, which produces a voltage from 100mV to 10 volts. Other scale factors are also possible. . . Circuit by Dave Johnson P.E.-June, 2000
Pushbutton Oneshot & Latch - This circuit uses a single IC to convert a noisy pushbutton switch signal into a clean pulse or a sustained push on-push off signal. It can operate from 3v to 18v. . . Circuit by David A. Johnson P.E.-March, 2002
Retriggerable Monostable Multivibrator Quickly Discharges Power-Supply Capacitor - 03/20/08 EDN-Design Ideas - A simple circuit consisting of a one-shot and a power MOSFET discharges the filter capacitor of a mains-powered power supply Design by Jordan Dimitrov, Tradeport Electronics, Vaughan, ON, Canada
SCR Flipflop for Alternating Flashing Light Bulbs - Schematic only __ Designed by G.L. Chemelec
Servicing Vibrator Power Supplies - From Radio Electronics, May 1950, this article gives a good description of vibrator supplies and the associated waveforms. __ Contact: blehack @ yahoo dot com
Set Reset Flip flop - This is an example of a set/reset flip flop using discrete components. When power is applied, only one of the transistors will conduct causing the other to remain off. The conducting transistor can be turned off by grounding it's base through the push button which causes the collector voltage to rise and turn on the opposite transistor. __ Designed by Ashish Parab
Slotted Opto-Sensor used in Honeybee Counter - I designed a circuit similar to this one a long time ago to help a beekeeper count the number of bees going into or out of a hive. The low power circuit uses a slotted opto-sensor to detect the passing bees. The circuit advances an electronic counting . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2000
Stable Multivibrator IC - I will introduce the a-stable multivibrator circuit which used inverter IC. This is the circuit to make do the blink of LED (Light Emitting Diode) with the a-stable multivibrator circuit which used inverter IC. __ Designed by Seiichi Inoue
Stable Multivibrator Transistor - I will introduce the a-stable multivibrator circuit which used two transistors. The a-stable multivibrator is the circuit which repeats the high level (H) condition and the low level (L) condition alternately. ‚hIn case of the transistor type, the voltage (Vcc) of the power supply __ Designed by Seiichi Inoue
Time to Dust - I have used the circuit below for many different applications, which require ultra low power drain. It uses a single CA4013 flip/flop. One section forms a pulse generator. The generator produces 100uS pulses at a rate of about 1 per second . . . Hobby Circuit designed by Dave Johnson P.E.-May, 2006
Timer for Darkroom Camera Shutter - This circuit was designed to control a film exposure shutter for a darkroom. It has 8 time steps ranging from 0.35 seconds to 4 seconds. It is activated by a foot switch and draws power from an external 12-volt DC supply . . . Hobby Circuit designed by David Johnson P.E.-June, 2000
Touch Activated Switch - This circuit provides about one watt of non-isolated DC power for an automotive type 12v LED array lamp in addition to a standard incandescent table lamp.. . . Circuit by David A. Johnson P.E.-January, 2002
Turn D-Flip/Flop into a One Shot Circuit - Yes you can use cheap D flip/flop logic circuits as nice one-shot pulse generators. This schematic shows how the popular CD4013 and the CD74HC74 can be used to generate pulses ranging from nanoseconds to seconds . . . Hobby Circuit designed by Dave Johnson P.E.-June, 2000
Two Transistor Oscillators - This page has two unusual two-transistor oscillators. I set the component values for a low frequency application. Both circuits draw only about 1 micro amp of current. . . Circuit by David A. Johnson P.E.-December, 2002
Two-Transistor Low Power Oscillators - This page has two unusual two-transistor oscillators. I set the component values for a low frequency application. Both circuits draw only about 1 micro amp of current . . . Hobby Circuit designed by Dave Johnson P.E.-December, 2002
Ultra Low Power Astable Multivibrator - Taking advantage of some new voltage comparators, this circuit can produce a nice square wave signal while drawing only 1.6 micro amps. With the inclusion of a diode, the circuit can also produce short pulses instead of a square wave signal. . . Circuit by David A. Johnson P.E.-December, 2004
Very Low Power Astable Multivibrator - This classic circuit draws only 200 nanoamps from a 1.5v supply. . . Circuit by David Johnson P.E.-June, 2000 |