Measure
Radio Wave Alarm
Description:
This simple circuit is sure to have the police beating a path to your door- however, it has the added advantage of alerting you to their presence even before their footsteps fall on the doormat. More >
Electronic Door Release
Description
The IC is a quad 2 input “AND” gate, a CMOS 4081. These gates only produce a HIGH output, when BOTH the inputs are HIGH. When the key wired to ‘E’ is pressed, current through R1 and D1 switchs Q5 on.The relay energises; and Q5 is ‘latched on’ by R8. Thus, the Alarm is set by pressing a single key,say one of the two non-numeric symbols. More >
Dark Activated Switch
This circuit will activate a relay when light falls to a preset level. Light level can be adjusted with VR1 and the relay contacts may be used to operate an external light or buzzer. More >
Frost Alarm activated switch
A simple thermistor triggered switch with adjustable threshold. It triggers with cold temperatures so may be used as a frost alarm or cold temperature switch. More >
Relay Driver circuit
One of the serious problems in relay operated circuits is the relay clicking or chattering during the on/off of the relay driver transistor. This problem is severe if the input circuit is a light / temperature sensor. During the transition of light / temperature levels, the relay clicks which may cause sparking of contacts. By using a simple tip, this problem can be avoided. More >
Micro-GT servo motor driver
Hi guys, this is a project from Italy, sent by Marco Gottardo. It is about the Micro-GT servo motor driver (or controller) and it is described as the best robotics power and economic solution, perfect like 14 servomotor driver. Now lets go through this project. More >
Light sensor switch circuit
This light sensor switch circuit allows the automatic connection of a lamp when the light is low (at nightfall) and will maintain the lamp ON for a certain period of time. More >
Touch light dimmer circuit
With IC SLB0586A from Siemens you can build a simple touch light dimmer circuit that will allow you to adjust the lamp intensity. Together with a TIC206D triac, it enables smooth regulation of light intensity from a bulb of 10W – 400W. A coil of 100µH/5A is required to suppress switching noise. More >
Temperature controlled relay circuit
This temperature controlled relay circuit is a simple yet highly accurate thermal control circuit which can be used in applications where automatic temperature control is needed. The circuit switches a miniature relay ON or OFF according to the temperature detected by the single chip temperature sensor LM35DZ. More >
Simple water detector circuit
This simple water detector circuit uses alternative voltage in order to prevent the corrosion of the electrodes. It is easy to build and uses N1 as a trigger Schmitt gate which generate the AC. If between the electrodes is a electricity conductor, for example an aqueous solution, then because of the rectification action of D1 and D2, the C4 capacitor is charging. More >