FREE
circuits!
Recently added diagrams and projects
October 4, 2010
The finish line circuit detects the first of three cars to cross the line and illuminates a 25 watt 120 VAC lamp indicating the winning lane. Three photo transistors are used which can be embedded... [more]
October 4, 2010
In this fire alarm circuit, a Thermistor works as the heat sensor. When temperature increases, its resistance decreases, and vice versa. At normal temperature, the resistance of the Thermistor (TH1) is approximately 10 kilo-ohms, which... [more]
circuit from:http://www.extremecircuits.net/2009/07/fire-alarm-using-thermistor.html
October 4, 2010
This circuit, enclosed into a small box, is placed in the fridge near the lamp (if any) or the opening. With the door closed the interior of the fridge is in the dark, the photo... [more]
circuit from:http://www.extremecircuits.net/2009/08/fridge-door-alarm-circuit_21.html
October 4, 2010
The circuit, enclosed in a small box, should be placed in the fridge near the lamp (if any) or close to the opening. With the door closed, the interior of the fridge is in dark,... [more]
circuit from:http://www.extremecircuits.net/2010/01/fridge-door-alarm-schematic-2nd-version.html
October 4, 2010
It beeps if the fridge door is left open for too long or hasn't closed properly, to stop food from spoiling. There are lots of other uses as well. A refrigerator or freezer door that... [more]
October 4, 2010
Whenever AC mains supply fails, this circuit alerts you by sounding an alarm. It also provides a backup light to help you find your way to the torch or the generator key in the dark.... [more]
circuit from:http://www.extremecircuits.net/2010/05/mains-supply-failure-alarm.html
October 4, 2010
This circuit is intended for children fun, and can be installed on bicycles, battery powered cars and motorcycles, but also on models and various games and toys. With SW1 positioned as shown in the circuit... [more]
circuit from:http://www.extremecircuits.net/2009/12/two-tone-siren-circuit-schematic-using.html
October 4, 2010
Although modern integrated circuit operational amplifiers ease linear circuit design, IC processing limits amplifier output power. Many applications, however, require substantially greater output voltage swing or current (or both) than IC amplifiers can deliver. In... [more]
circuit from:http://www.extremecircuits.net/2010/05/op-amp-booster-designs.html
October 4, 2010
Typically the op-amp's very large gain is controlled by negative feedback, which largely determines the magnitude of its output ("closed-loop") voltage gain in amplifier applications, or the transfer function required (in analog computers). Without negative... [more]
circuit from:http://www.extremecircuits.net/2010/05/upto-73-op-amp-circuit-collection-pdf.html
October 4, 2010
For a collector follower with emitter resistor, you’ll often find that the gain per stage is no more than 10 to 50 times. The gain increases when the emitter resistor is omitted. Unfortunately, the distortion... [more]
circuit from:http://www.extremecircuits.net/2010/05/10000x-with-one-transistor.html
All posts