This timer circuit draws only 3 µA of current, and can be powered by DC supplies ranging from 3 V to 15 V. The circuit produces accurate pulses whose time can easily be adjusted, based on the R1 × C1 time constant. The time should not ...
This basic beat oscillator makes continuous wave keyed code and single sideband suppressed carrier signals audible. A recent Design Idea from contributor Gavin Watkins shows an inexpensive add-on beat frequency oscillator (BFO) [ 1 ] for ...
Expensive shortwave radios include beat frequency oscillators, so why not also add one to an inexpensive radio version? Broadcast shortwave (SW) radio use may be declining, but there are still lots of interesting signals to listen to between 1.6 ...
This proposed design eliminates traditional additional requirements for AGC, AC coupling, and post amplification circuitry. This Design Idea presents a simple op-amp-based sine wave oscillator that directly generates a low-impedance bipolar output ...
This circuit enables you to generate remote control PWM test signals with a (very) generic (and cheap) chip. A recent Design Idea ( Ref. 1 ) illustrated the application of an interesting chip (the LTC6992 ) to remote control (RC) PWM test signal ...
This page has two unusual two-transistor oscillators. I set the component values for a low frequency application. Both circuits draw only about 1 microamp of current. Materials on the topic Datasheet Fairchild 2N3904 Datasheet Fairchild 2N3906 ...
Let’s melt metals using the ZVS (Zero Voltage Switching) technique applied to a 1,000 W RLC resonant circuit. Have you ever wondered how intense the electromagnetic fields surrounding us can be? This is a relevant question, considering we are ...
A while back I was challenged by a visitor to the website. He needed a very loud sweeping siren type audio sound generator powered by 3 V. He tried some of the commercial sirens but they were not very loud when powered by 3 V. He also said that ...
It is well known that a 555 timer in astable mode can be frequency modulated by applying a control voltage (CV) to pin 5. The schematic on the top of Figure 1 shows this classic 555 VCO. Modulating pin 5 has some severe drawbacks: The control ...
There are many ways of generating analog sawtooth waveforms with oscillating circuits. Here’s a method that employs a single supply voltage rail to produce a buffered signal whose frequency can be varied over a range from 10 Hz to 1 MHz ...