Free electronic circuit design and schematic diagram
This true stereo indicator is different from what we usually find on FM radio receiver, which is usually a pilot tone detector. A stereo broadcast from FM radio station contain pilot tone, but a presence of pilot tone doesn’t necessarily a stereo broadcast signal since a mono FM transmitter ca broadcast pilot tone as well. Since this circuit detect the […]
Read more
This is a audio-controlled lamp circuit. This circuit requires low voltage input such as pre-amplifiers, tone control, or general audio line level output. It’s also possible to feed the input with signal from small power amplifier output, or high power amplifier witk low volume level. The characteristic of lamp dimming (incandescent lamp) will look like coming from proportional controller since […]
Read more
This is a Stereo VU Booster circuit. In this circuit, shown in the schematic diagram, transistor FCS9014 is used. Actually you can use almost any type of small signal NPN transistor. This transistor usually used for regulator and pre-amp circuit. Here is the schematic diagram of the circuit: The schematic diagram show only one channel, so you have to build […]
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
This is a circuit of Audio Decibel Level Meter. This circuit uses the SA604 which not only designed as an RF device but also the Received Signal Strength Indicator (RSSI). In a cellular radio, the radio’s microcomputer uses that function to monitor the received signal strength continuously. A logarithmic response proportional to the input signal level is given by this […]
Read more
AN6884 is a logarithmic scale LED bar display driver. AN6884 accept wide range of supply voltage, ranging from 3.5V to 16V. This VU (voltage unit) bar display circuit provides only 5 levels, but will accept wide range of input level because the scale is logarithmic: -10, -5, 0, 3, and 6dB points. The output current for each LED will be […]
Read more
Using this circuit, you can measure the actual output power of your amplifier. You can put this circuit in a box as a measurement instrument, or you can integrate it inside your power amplifier to get real power display. The circuit’s schematic diagram is shown in the figure below. This circuit would be a handy instrument for audio engineer, for […]
Read more