DC Motor Controller using Transistor TIP31

This is a DC motor controller circuit, built using transistor TIP31 based on H-Bridge concept. The switch S1 and S2 are normally open , push to close, press button switches. The LED function is to indicate the direction of motor rotation, you may use any common LED type. The TIP31 transistors capable to handle 3A… Read More »

5W Simple Inverter

Here’s a very simple circuit inverter that converts DC current into AC current, from 12V DC to 220V AC with output power of 5W max. Inverter circuit is typically used for emergency lighting, since the power output is small, which is about 5W only. But you can use this inverter for other purposes that do… Read More »

Nokia Cell Phone

This is the Nokia cellphone wiring diagram collection. Fixing a cell phone is basically not a difficult thing. All you need is proper equipment, basic knowledge of electronics and of course a manual guide, including schematic diagrams. Nokia is one of the largest mobile phone manufacturer in the world. The products are very diverse, lots… Read More »

15W FM RF Amplifier with 2SC2539

This is a 15W FM RF amplifier circuit which build based on RF Power Transistor 2SC2539. 2SC2539 is a silicon NPN epitaxial planar type transistor designed for RF power amplifiers in VHF band mobile radio applications. FM RF Amplifier Circuit Diagram: Coil Specifications: L1: 2T Coil diameter:4mm L2: in series 6pcs Toroidal ring L3: 4T… Read More »