Economy radar detector

This circuit uses a 1458 dual op-amp to form a radar detector. C1 is the detector of the radar signal. The first op-amp forms a current-to-v...

Automatic Gate Light With A Musical Bell

This circuit may be used to auto- matically switch on a light at the enterance gate to a premises, at night, by sensing the presence of a pe...

A Highly Efficient DC Lamp Dimmer

The simplest lamp dimmer cir- cuit consists of a rheostat, in se- ries with the lamp, which one may adjust to obtain the required brightness...

Suitable for alerting purposes Drives 12V Car bulbs

Parts: R1 6K8 1/4W Resistor R2 220K 1/4W Resistor R3 22K 1/4W Resistor C1 100µF 25V Electrolytic Capacitor C2 10µF 25V Electrolytic Capacito...

Motorcycle Low Voltage Warning

Parts List: U1 = LM339, Op-Amp Q1 = 2N3906, PNP transistor. D1,D2 = 1N4148, signal diode ZD1 = 1N5235, 6.8V zener diode R1 = 1K R2 = 10K, tr...

Christmas Lights Tester

Like every year around the same time, I hurried to get my Christmas tree all set up and the first thing we do when the tree is 'standing...

Birdie Doorbell Ringer

Notes P1 is of experimental value. Start with 220 Ohms or so and modify to suit your needs. The transistor is a general purpose kind and is ...

Car Backup Alarm

The brake lights of the automobile trigger this circuit on and off. This save the annoyance of the alarm when it is not needed. This is an o...

Alarm Power Supply

Description: A 12 Volt power suppiled designed for Ron's Modular Burglar Alarm. However, being a popular supply voltage this circuit wil...

Hijack Alarm

Description: This circuit is designed primarily for the situation where a hijacker forces the driver from the vehicle. If a door is opened w...

5 Zone Alarm Circuit

Each zone uses a normally closed contact. These can be micro switches or standard alarm contacts (usually reed switches). Zone 1 is a timed ...

Ultrasonic Dog Whistle

It's well known that many animals are particularly sensitive to high-frequency sounds that humans can't hear. Many commercial pest r...

'Beeper' Using 1C 555

Here is a 'beeper' circuit employing two 555 ICs. It can be used in various circuits (having supply voltage of 5 to-15V DC) that req...

Strobe Light

A simple electronic strobe light for dancing lovers can easily be constructed by using a timer 1C 555 and a triac. The cost of the circuit d...

Regulated Power Supply With Dual Purpose LED

For most electronic circuits and equipments, regulated power supplies are a must. For voltage references required, the usual procedure is to...

Audio Level Indicator

It is interesting to listen to your favourite music on a stereo system. It may be probably more interesting if you can watch the dancing lig...