MCU programmer taps power from PC’s serial port
Even with the serial port's limited capacity, serial-port power can still be a convenient power source for today's electronics. Here's…
Precise over-voltage protection with circuit breaker
Read about a simple circuit breaker that delivers precision over-voltage protection and over-current protection.
Detect leakage of capacitors, semiconductor switches
The low input-bias current of a voltage-follower op amp enables this simple fixture to measure the leakage current of capacitors.
Enabling a simple ohmmeter with gigohm range
Through the use of an external counter and control circuitry, this system can measure resistances in the tens of gigohms.
Comparator identifies peaks, valleys in waveform
In this article, we present a simple comparator circuit that locates peaks and valleys of a waveform in time.
Testing low-current power supplies
Use this simple dual constant-current-load design, which can be built with inexpensive, common parts.
Two transistors make up high-precision, ac-mains ZCD
Here is a simple two-transistor circuit that can accurately detect the zero crossing of the ac mains voltage.
Spark current-ratio-to-frequency converter with integrator
Here is a precision integrator that generates a pulse train whose frequency is proportional to the ratio of two input…
RC lowpass filter expands MCU’s output port
A simple lowpass RC filter enables a single output pin of a microcontroller to expand the number of output bits.
Recycle potentiometers as handy voltage sources
Read about a circuit that recycles old precision potentiometers that have direct-reading scales into useful laboratory "volt boxes".