The tuning of your guitar, guitar or any other instrument can be done much more accurately with an electronic tuning fork. This circuit generates exact frequency signals corresponding to the seven notes of the octave you choose and serves as the standard for tuning musical instruments. Powered by common batteries, this is a fully portable and independent device, because it incorporates its own amplifier.
Most amplifier designs or even types obtained in kits do not include an appropriate tone control. When many have a passive tone control that first attenuates certain frequencies than reinforces them; acting in an inverse way to the desired one. The simple tone control that we describe can be the ideal solution for the project of the reader that needs this feature, but without loss and with good audio quality.
This interesting circuit causes a fluorescent lamp to blink at regular intervals, with power from 12V battery. We can use it as an excellent signaling device for, works on public roads, in troubled vehicles and even to draw attention in shop windows. The circuit is compact and can easily be housed in a small box.
This relay closes its contacts only when signals from a narrow range of frequencies around the selected value are applied to the input. We can use this circuit in remote controls modulated by tone, selective activation with single cable of control and in fines other applications that involve from the recreation to the professional use.
Research done in American laboratories has revealed that rodents do not like high-frequency, high-intensity sounds. As animals can hear these sounds, but we humans do not, a powerful ultrasonic generator like the one described in this article serves to chase rodents.
A special National Semiconductor Integrated Circuit enables the activation of LEDs with 1.5 V voltages opening up to a huge range of interesting assemblies. See in this article the basic design of a flasher with this component.
This circuit uses a sensitive reed relay to control external loads. The time delay is given by the...
This circuit was found in an old publication about transistor. The original trasistors are...
This conventional astable uses two NPN transistor and was found in a publication of the year 1968. The...
This basic configuration of an astable multivibrator was found in a publication of the year 1968....
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...
This simple timer can be used in many applications such as egg timer. The LED glows up when S1 is...
The circuit shown by the figure below can produce signals in the range between 20 kHz and 30 kHz....