Free electronic circuit design and schematic diagram
This is a Basic Flash Memory Programming Voltage Supply circuit. This circuit uses LT1072 switching regulator to generate high voltage by driving the L1. R2 and R2 provide DC feedback for this circuit. R3-C2 and C1 control the SC roll-off. This circuit can generate supply of 12V or 12.75V depended on the R1 values. To protect this circuit from the […]
Read more
Voltage step-up also employed in figure below, but for a different purpose. The common requirements are transmission of industry standard 4-20mA current loop signals to valves and other actuators. Current transmitters is required by resistive line losses and actuator impedance to be able to force a compliance voltage of at least 20V. 5V powered systems usually cannot meet current […]
Read more
This is a compressor circuit that can be used for dynamic mic, condenser mic, or electric guitar pickup. This circuit doesn’t produce very good sound output, but it has very stable amplitude/volume. This compressor circuit design is unique since it uses base current control for manipulating the gain. Here is the schematic diagram of the circuit: The first and second […]
Read more
Door intercom is very useful for home security. If you receive a door knock or door bell/alarm, you can push this intercom knob and ask the guest to identify his/her self, before deciding to open the door to welcome. Here is the schematic diagram of the circuit: To install this door intercom, except for right side speaker, you should place […]
Read more
We can use a circuit breakers to limit the current in a single circuit in most household applications. Although breakers come in many sizes, typically a single circuit is limited to 20 amperes. This means that to bend it downward and release the spring-loaded trip-lever, 20 amps of current will heat the bimetallic strip. Another mechanism is employed to handle […]
Read moreThis is a aircraft band receiver video. This video shows step by step how to modify the transistor radio so that the radio can receive the transmission radio from the air traffic control tower. Normally, to pick up the transmission radio from the air traffic control tower, the special radio or scanner. This video uses FM transistor radio. First the […]
Read moreThis is a video about how to hack the 12V battery. Using the 12V battery, the $40 can be saved. First, pull the case of the battery using screwdriver and pulling the back. You will find the eight 1.5V cell battery. The cell batteries that hacked from 12V battery can be used to power six devices. Here is the video:
Read more