This is a very useful device for those who have extension on their telephone line, wants to maintain their privacy and, in addition, have some feature to warn when someone is occupying the line. Simple to assemble, it is powered by two common batteries and as its consumption is very low in the standby condition, its durability is very great.
This noise transmitter produces a signal that covers all the frequencies of the FM range within a few tens of meters, thus preventing the action of small spy transmitters that may be in action at this location. Another possible application for this circuit is as a test for receivers or other devices that may be subject to interference.
Oxygen sensors find a wide range of domestic use (gas leak detectors), industrial and automotive. See in this article how they work and how these sensors are used.
Simplified battery-eliminating power supplies without the need for an isolation transformer can be useful in a number of practical, low-power applications such as powering LEDs, small motors or electronic circuits that do not need to be regulated, etc. Of course, only the applications in which the safety that an isolating transformer provides should be taken into account such as calculators, clocks, etc. The source we describe can power circuits that require voltages of 3 to 12 volts with currents up to about 200 mA.
This circuit makes a powerful xenon lamp produce intense short-term flashes for signage, at dances or in shop windows. The circuit uses common components.
This circuit heats a wick of a small bottle of essence, causing it to evaporate and produce a pleasant scent that spreads through the environment, having an automatic activation at regular intervals.
This amplifier is from a 1973’s Japanese magazine. The transistors are of the time and the power...
We found this circuit in documentation from the 1970s; The circuit uses Japanese transistors of...
This circuit was found in a Japanese documentation of the 70's. It uses transistors of the era and is...
This small power amplifier makes use of an output transformer given its design time. In fact, the...
The power source shown for powering for small TTL circuits was found on a Radio Electronics...
IGBTs are widely used in frequency inverters, power controllers, switched sources and DC/DC...
This oscillator can run in frequencies up 10 MHz depending on the Power supply voltage. The 1 µF...
This one-digit counter is part f the samples bench of the MultiSIM in one of its versions. The...