Most electronic clocks, be they analog or digital, use a crystal oscillator (XO) based on a 32.768 kHz crystal for their reference. In fact, it is same crystal that’s commonly used as a real-time clock for many microcontroller systems. These ...
Conventional astable oscillator circuits that use CMOS logic gates, bipolar transistors or low current op Amps, often require more current than necessary. The circuit shown generates a low frequency square wave signal while drawing only 0.5 ...
We recently saw how certain audio power amplifiers can be used as oscillators ( Ref. 1 ). This Design Idea shows how those same parts can be used for simple amplitude modulation, which is trickier than it might seem. The relevant device is the ...
There are multiple means of generating analog sawtooth waveforms. Here’s a method that employs a single supply voltage rail and is not finnicky about passive component values. Figure 1 shows a pair of circuits that use a single 3.3-V supply ...
In the first part ( Ref. 1 ) of this Design Idea (DI), we saw how to use the TDA7052A (or similar) power amp to build a minimalist siren-type power oscillator, and also, having looked at that device’s distortion characteristics under various ...
When audio power amplifiers oscillate, the result is often smoke, perhaps with a well-cooked PCB and a side order of fried tweeter. This two-part Design Idea (DI) shows some interesting ways of (mis-)using a common power amp to produce deliberate ...
One classic set you’ll see in most гvintage mystery movies is an interrogation room with a “two-way” mirror in one wall. This cool gadget lets the witnesses see the suspects from another room while the suspects can see only ...
In Part 1 of this Design Idea [ 1 ], we saw how a standard electret microphone capsule can be persuaded to detect infrasonic signals down to a fraction of a Hertz by adding some fairly simple equalization. In this second and concluding part, we ...