Search Results for : LM317

Introduction The objective of this project is to use inexpensive PIR sensor to detect if a human has moved. To build this project I use a PIC18F25K20 microcontroller to detect if the sensor had change state and it will emit a sound from the speaker or piezo, the MCU also detect the...

This project is a solution to power up most of devices or projects requiring dual (+/-) adjustable power supply. Description The circuit is based on LM317 positive and LM337 negative voltage regulators. LM317 series of adjustable 3 terminal regulator is capable of supplying in...

This project is a controller for a dual pulse spot welder that has some nice features that are controlled using a LCD interface. Description I always wanted a spot welder, so I decided to built one. I wanted to build a capacitance discharge one but I couldn’t afford for the...

Description The above pictured schematic diagram is just a standard constant current model with a added current limiter, consisting of Q1, R1, and R4. The moment too much current is flowing biases Q1 and drops the output voltage. The output voltage is: 1.2 x (P1+R2+R3)/R3 volt....

Description Voltage regulators such as the LM78xx, and LM317 series (and others) sometimes need to provide a little bit more current then they actually can handle. If that is the case, this little circuit can help out. A power transistor such as the 2N3772 or similar can be used...

  Introduction I have been using the toner transfer method for about 9 years with great results. Occasionally I would need a board with finer traces and I would use UV method. My exposure setup allowed only a single sided board to be made and it was composed of a 30cm UV tube,...

The microcontroller used is 0822 zilog encore! 8k series (soic,28pin) as shown on the figure. Is a programmable microcontroller, the functions used are the GPIO and the UART of the chip. GPIO is used on led indicators, and the UART is used for giving and reading AT COMMANDS to control...

This project is a temperature controller for a PC FAN. It regulates the speed of the FAN attached to it according to the measured temperature. Temperature is sensed using a simple NTC thermistor. Description In most PCs, the fan runs constantly, which may not be necessary. A...