The "card" type power saving controller for hotel guest rooms introduced in this article can be installed at the door of the guest room. The "card" is together with the key. When the guest enters the '...

This circuit has a simple structure, easy materials, reliable performance and convenient operation. Working principle: Assuming there is no water in the water tank and water needs to be preheated, jus'...

This article introduces an energy-saving circuit for controlling the operation of classroom fans. According to the requirements, the fan can be designed to automatically operate when the temperature r'...

The electronic fly killer uses high-voltage pulse voltage applied to the power grid to kill flies that touch the net. When in use, bait is set inside the net to attract flies, and all flies that fly o'...

The whole controller consists of three parts: signal control for opening, closing and stopping, protection circuit and driving circuit. The opening, closing and stopping of the telescopic door are con'...

I bought a YAMAHA150 motorcycle and after using it for a while, I felt that everything was good, except that the light was not bright enough. It was almost off at low engine speed. I changed it to a g'...

Advertising colored lights production circuit diagram description: 1. Each 8050 transistor can drive twelve to twenty-four light-emitting diodes. If Q1 and Q2 are changed to 9013, the driven light-emi'...

As shown in the figure, it is an 1880MHz internal collector bias amplifier application circuit composed of RF2324. The RF signal (RF) is input from pin 3, and passes through the preamplifier, the fina'...

As shown in the figure, this is the LM4902 differential input audio amplifier circuit. The audio signal is input to the IN terminal and the -IN terminal in a differential form.

The circuit in the figure uses a dedicated colorful LED flash control chip HL081LF. HL081 is a synchronous colorful flash integrated circuit manufactured using CMOS technology. With the red, green and'...

In order to simplify the production, the switching power supply is designed to be unable to automatically stabilize the voltage. Its function is similar to that of a transformer, but it only realizes '...

I have several 2.4V/280mAh NiMH batteries and plan to make a simple constant current charger. I can't find a Zener diode at the moment, so I'm considering using a light emitting diode instead of a Zen'...

The exciter of FM302E-I FM transmitter adopts HPB-1210 motherboard of NEC Company of Japan. The carrier is directly modulated, and phase-locked frequency stabilization and frequency synthesis technolo'...

I have designed an automatic water pumping control circuit with only two signal lines. It is used to control my own water pump and has stable and reliable performance. I would like to introduce it to '...

This wireless mouse/keyboard does not need to make any changes to the appearance and internal circuit of the original mouse when making it. It is easy to use and reliable, and is very suitable for hob'...

There are two P-type and N-type field effect transistors inside the integrated circuit. If a negative feedback bias resistor is added between the output terminal and the input terminal of the inverter'...

The original alternating current power supply system of the machine has a rectified and stabilized output voltage of DC19V (3.15A); now it uses two 12V 20Ah maintenance-free batteries connected in ser'...

The spot welding machine has three levels of power adjustment and a fine adjustment knob. The circuit design is clever and the production is not complicated. Its working principle is capacitor energy '...

As shown in the figure, it is a 16-level priority encoding circuit composed of an 8-bit priority encoder CD4532 and a four-2 input OR gate CD4071. This circuit is mainly used in digital systems. In th'...