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 ...
A few months back, frequent DI contributor Nick Cornford showed us some clever circuits using the TDA7052A audio amplifier as a power oscillator. His designs also demonstrate the utility of the 7052’s nifty DC antilog gain control input: ...
The versatility of the venerable LMC555 CMOS analog timer is so well known it’s virtually a cliche, but sometimes it can still surprise us. The circuit in Figure 1 is an example. In it a single linear pot in a simple RC network sets the ...
By changing the supply voltage fed to a classic 4584 Schmitt trigger type oscillator, the oscillator frequency can be changed over a range of 50:1. A 74HCU04 inverter is used at the output of the 4584 to maintain a constant TTL logic level signal. ...
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 ...