Rongge

This is a simple Yet Useful Video Switcher Circuit Diagram. With the cost of security cameras going down, adding a surveillance system for your store, office or home is becoming more practical all the time. However, you might be dismayed at the thought of having to buy a monitor for every camera that’s installed. dedicating a single monitor to a single camera also runs the risk of burning the camera’s image into the phosphor screen of the CRT. If you prefer a single monitor instead of the “NASA-Mission Control” look, you could buy a special monitor that has a video switcher built in. That type of monitor can automatically switch between several camera inputs in sequence.  Useful Video Switcher Circuit Diagram With that type of arrangement, you’d have to watch only one screen instead of having to scan a wall of CRTs. Switching between several cameras would also prevent image burn-in on the monitor. Those types of monitors, unfortunately, are also very expensive, offsetting the cost ...

This is a very low cost and basic from of home automation allowing you to turn on and off lights and other devices using your computer or mobile phone. It has been built and tested use using UK power plugs, but the same protocol is used on many budget remote power switchers from around the world. [ ]

This circuit was devised to switch power to a Peltier cooler in a vehicle. Power to the load from the vehicle’s battery is switched by a SPDT relay while the ignition switch is turned on and from the SLA auxiliary battery when the ignition is off. The SLA battery is charged from the vehicle’s battery. When the engine is running, the voltage remains fairly constant, which greatly simplifies the charging circuit. If the SLA battery is fully charged, any further charging current from the vehicle battery is limited by a 3.3W 5W resistor (R1). If the SLA battery is deeply discharged, the voltage drop across this resistor will be enough to bias on PNP transistor Q1. This will turn on P-channel Mosfet Q2 and it will provide further charging current via R2, effectively becoming a 2-step charger. Since the paralleled resistors (R1 & R2) have a lower combined voltage drop, Q1 will receive lower base bias, which in turn will cause Mosfet Q2 to fully saturate. This positive feedback creates a ...