Sometimes the need arises to construct a really simple oscillator. This could hardly be simpler than the circuit shown here, which uses just three components, and offers five separate octaves, beginning around Middle C (Stage 14). Octave # 5 is missing, due to the famous (or infamous) missing Stage...
Simple L200 Charger
This circuit came about as the result of an urgent need for a NiMH battery charger. No suitable dedicated IC being immediately to hand, the author pressed an L200 regulator and a 4.7 kΩ NTC thermistor into service. Those components were enough to form the basis of a charger...
Simple Infrared Remote Control Extender
This ultra-simple remote control extender is ideal for use with a hidden video recorder. The recorder is a Panasonic NV-SD200 and is used as part of a camera surveillance system. A PICAXE-08-based circuit is used to detect events and control the recorder. It also flashes a LED near the monitor to indicate...
Simple Water Activated Alarm
The circuit uses a 555 timer wired as an astable oscillator and powered by the emitter current of the BC109C. Under dry conditions, the transistor will have no bias current and be fully off. As the probes get wet, a small current flows between base and emitter and the transistor switches on. A larger...
Simple Gate Alarm
Description:A cheap and simple gate alarm made from a single CMOS Integrated Circuit.Figure 1 represents a cheap and simple Gate Alarm, that is intended to run off a small universal AC-DC power supply.IC1a is a fast oscillator, and IC1b a slow oscillator, which are combined through IC1c to emit a high...
Simple 12V DC to 220V 100W Inverter
This is 100W inverter circuit. It uses 4047 IC and IRF540 Mosfet instead of 2N3055 transistor. Power output is 100W from 2-3A transformer. &nb...
Simple Car Battery Voltage Monitor Circuit
This circuit is used to monitor the battery voltage to display a dual-colored LED status of the battery to. If the LED “green”battery voltage exceeds 11.9 volts. If the yellow LED, battery voltage 11.9 to 11.5 volts. If the LED is “red” If the battery voltage below 11.5 volts. You can of course change...
555 timer IC Based Simple Servo Controller
555 timer IC Based Simple Servo ControllerServos became valuable products for any variety of plans, like robotics, automation or only remotely controlling some thing, for example model vehicle steering. Theyre reasonably low-priced and also simple to have hold of, however controlling them can be a little...
Simple Lead Acid Battery Charger 1
Except for use as a normal Battery Charger, this circuit is perfect to constant-charge a 12-Volt Lead-Acid Battery, like the one in your flight box, and keep it in optimum charged condition. This circuit is not recommended for GEL-TYPE batteries since it draws to much current. The above circuit...
Simple 240VAC TO 5VDC POWER SUPPLY
This is simple way to power some 5v logic from a 240vac source. If a 120vac power adapter is used, the circuit will also work for 120vac power lines. 240VAC TO 5VDC POWER SUPPLY,...
Simple Police Siren
The simple Police Siren circuit uses two 555s to produce an up-down wailing sound. The first 555 is wired as a low-frequency oscillator to control the VOLTAGE CONTROL pin 5 of the second 555. The voltage shift on pin 5 causes the frequency of the second oscillator to rise and fa...
