LED Running Display Using NE555

Here's a circuit to build a led based running display using easily available general purpose timer IC NE555 and a popular decade counter IC CD4017. This display consist of 24 LED's of four layers. The NE555 is wired as an astable multivibrator whose output triggers CD4017 counter.

Powerful Pest Repeller Circuit

Most of the electronic pest repeller circuits have a major drawback of low power output hence their effectiveness suffers. The ultrasonic pest repeller circuit described here generates powerful ultrasonic signals therefore efficient to repel pests like mosquitoes. In addition to the ultrasonic frequency oscillator, we use a  separate push-pull power amplifier and transformer  to boost ultrasonic signals.

Voltage Transfer Circuit

This circuit uses to supply small voltages to LEDs or other low power devices in the situation when we cant connect the power supply directly to it. Ideally this uses the theory of voltage transfer using an oscillator and a toroidal transformer.

Temperature Controlled Soldering Iron Circuit

Every technician uses soldering iron in different power rates such as 10W, 20W, 25W, 30W etc. It is very difficult to change the soldering iron each time with specific uses. Here is a solution to this problem by assembling a simple temperature controlled soldering iron circuit which enables you to use your soldering iron in variable power rates from 10w to 35W.

Low Cost Metal Detector Circuit

Metal detectors are usually very complicated and it may be consist of very costly components and metal detector DIY circuits are rare. However this metal detector hobby circuit can be constructed by only a few components such as BC548 and an ordinary AM radio that we usually use.

Musical Car Reverse Horn Circuit

Want to make some stuff that fits your car or motor cycle? Then here is a simple musical horn circuit that can be connected to the 12V battery of any car or motorcycle. This circuit commonly used as reverse musical horn. Here we use a commercially very low cost musical IC UM66. But this Ic can only handle supply voltage below 4V. So we used a 7805 regulator ic for adjusting the voltage to 5V and its further reduced to 3.8 volt by connecting two diodes D1 and D2 then it will supplied to musical horn producer UM66.