Simple Electronic Circuit Breaker

Power source is insensitive to load changes

The circuit is analogous to a voltage or a current source but delivers fixed power levels that are independent of the load resistance. A feedback loop senses load power and automatically adjusts the output voltage to maintain the desired power level. The circuit measures the output current with a...

Slave Flash Trigger

The SCR is wired across the trigger circuit of the flash gun. Normally, the SCR is off, so the flash gun is able to cha

Synchronizing controller detects baud rate

A simple and inexpensive implementation using an eight-pin 12C508 controller (Microchip Technology, Chandler, AZ) provides both bit-rate detection and a synchronous, appended-clock output from an asynchronous input-data stream (Figure 1a).

Single-setpoint temperatre controller

The AD590 produces a temperature-dependent voltage across R (C is for filtering noise). Setting R2 produces a scale-zero voltage. For the Celsius scale, make R = 1 K and Vzero = 073 volts

Autotransformer regulator inverts 12V to produce ­12V

You can create a dc/dc regulator with an internal switching MOSFET that inverts 12V to produce an output of 200 mA at ­12V (Figure 1). The IC is a high-efficiency device whose low quiescent current (120 µA maximum) is the product of a CMOS process that limits the absolute-maximum...

Load switcher draws only 6 µA

Although it draws only 6 µA, the circuit in Figure 1 enables a small ac signal as low as ±1 mV to switch relatively large load currents. The circuit takes advantage of the IC`s very low quiescent current, which, at 1.2 µA maximum per amplifier, is less than the self-discharge of a typical...

Power down function

This circuit adds a power down function to analog I/O ports (for example, the AD7769 and AD7774). Moreover, the diodes ordinarily needed to protect the devices against power-supply missequencing can be eliminated Bringing the power down control high (+5V) applies power to the controlled...

Soft-Start Circuit For Power Amps

The delay time for all circuits shown has been revised. The optimum is around 100ms - sufficient for around 5 full cycles at 50Hz, or 6 cycles at 60Hz. It is also quite alright to run the transformer to around 200-500% of full load current at start-up, and the formulae have been revised for 200%....