Free electronic circuit design and schematic diagram
Based on the squaring property of two back-to-back diodes connected across output and inverting input of the op-amp, IC1B forms a rather straightforward fuzz circuit. The squared output signal coming from IC1B is converted into a triangle-shaped waveform by IC1C and related components. IC1D is wired as a virtual-earth mixer, summing the linear, squared and triangle-shaped signals coming from IC1A, […]
Read more
This is a decibel meter circuit. This circuit is used to measure sound pressure level (SPL) from about 60 to 70 dB. In this circuit, transistor stage and one LM324 op-amp section are used to amplify the sound that is picked up by an 8 ohm speaker. As voltage comparators, the circuit uses The remaining 3 sections of the LM324 […]
Read more
This circuit presents a very simple and useful stereo balance indicator circuit that is based on few common external components. This schematic circuit is very simple to build. An visual indication with LEDs for left , right and center balance is provided by this circuit. Outputs from each channel are fed to the two inputs of IC1 connected as a […]
Read more
They were missing a VOX if we are take a look at some of the budget priced HF transceiver. It would certainly be nice to have VOX capability although most of these budget priced transceivers performed admirably. The figure below show us a basic VOX circuit which will perform very well once the VOX level is set correctly. This is […]
Read more
There are many low power SSB rigs and kits don’t have any real speech processor circuitry, although there is a built in speech processor in most modern HF. Speech processing is an important thing, when the SSB is operated at low power to get through the QRM. Speech processing can be done by this circuit. This is a simple and […]
Read more
The X9314 with the low voltage LM386 power amplifier is shown on figure below. 250mW of audio power will be produced by this circuit with only a 5V DC source. Plenty of sound for intercom, communications, or monitoring applications will be provided by this circuit. It’s require a 74HC132 quad Schmidt NAND gate (U2) plus a few discrete components to […]
Read more
Try to imagine the possibilities to integrate full audio tone, balance, and volume control into your multimedia computer product, and you integrate it without having to resort to any manual knobs. Naturally we could integrate it with a bunch of DACs all running under microprocessor control, but what happens if the processor has had a chance to reload the preset […]
Read more