http://www.simplecircuitdiagram.com Free Simple Circuit Diagram Tue, 24 Jan 2012 02:31:05 +0000 en hourly 1 http://wordpress.org/?v=abc http://www.simplecircuitdiagram.com/2012/01/02/frequency-modulated-oscillator-for-fm-transmitter/ http://www.simplecircuitdiagram.com/2012/01/02/frequency-modulated-oscillator-for-fm-transmitter/#comments Mon, 02 Jan 2012 00:18:47 +0000 Rust http://www.simplecircuitdiagram.com/?p=2740 An oscillator can be built using LC (inductor-capacitor) tank circuit. When we vary the capacity of the capacitor in LC tank circuit then the frequency of the oscillator will vary according to capacitance change.  The idea of this modulator is … Continue reading →]]> http://www.simplecircuitdiagram.com/2012/01/02/frequency-modulated-oscillator-for-fm-transmitter/feed/ 0 http://www.simplecircuitdiagram.com/2011/05/23/50-khz-fm-optical-receiver/ http://www.simplecircuitdiagram.com/2011/05/23/50-khz-fm-optical-receiver/#comments Mon, 23 May 2011 01:13:19 +0000 Rust http://www.simplecircuitdiagram.com/?p=2593 Frequency modulation (FM) can be used to transmit analog voltage level signal with good noise immunity. The transmission itself  might employs different methods, and this circuit uses free air optical medium. This optical receiver circuit is built using a L14G2 … Continue reading →]]> http://www.simplecircuitdiagram.com/2011/05/23/50-khz-fm-optical-receiver/feed/ 0 http://www.simplecircuitdiagram.com/2010/07/12/wireless-telephone-line-spy/ http://www.simplecircuitdiagram.com/2010/07/12/wireless-telephone-line-spy/#comments Mon, 12 Jul 2010 02:18:06 +0000 Rend http://www.simplecircuitdiagram.com/?p=1249 This is a phone bug circuit. This wireless telephone line spy circuit can be used to transmit the phone conversation to a nearby FM radio. This circuit must connected to a normal phone line.  Here is the schematic diagram of … Continue reading →]]> http://www.simplecircuitdiagram.com/2010/07/12/wireless-telephone-line-spy/feed/ 0 http://www.simplecircuitdiagram.com/2010/05/19/two-transistors-fm-transmitter/ http://www.simplecircuitdiagram.com/2010/05/19/two-transistors-fm-transmitter/#comments Wed, 19 May 2010 02:24:28 +0000 Rust http://www.simplecircuitdiagram.com/?p=1160 Basically, this circuit is a radio frequency (RF) oscillator that operates around 100 MHz. The audio which is picked up and amplified by the electret microphone is fed into the audio amplifier stage built around the first transistor. Output from … Continue reading →]]> http://www.simplecircuitdiagram.com/2010/05/19/two-transistors-fm-transmitter/feed/ 0 http://www.simplecircuitdiagram.com/2009/05/28/single-chip-fm-transmitter-for-short-range-application/ http://www.simplecircuitdiagram.com/2009/05/28/single-chip-fm-transmitter-for-short-range-application/#comments Thu, 28 May 2009 04:34:54 +0000 Adam http://www.simplecircuitdiagram.com/?p=131 The FM transmitter circuit here works in the broadcast band 88 to 108MHz, and can be used to broadcast audio signals for remote listening.  The output power is around -21dBm, and the circuit operates with 3V power supply. Here is … Continue reading →]]> http://www.simplecircuitdiagram.com/2009/05/28/single-chip-fm-transmitter-for-short-range-application/feed/ 0