Free electronic circuit design and schematic diagram
Comparator with hysteresis (Schmidt trigger) can be built using LM339, LM239, LM2901, LM2901V, NCV2901, or MC3302 quad single supply comparator integrated circuit chips. Here is the circuit’s schematic diagram and formula: This circuit’s output will swing to high or low using two threshold values. If the last output is high, then the output can be changed to low if the […]
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If only a 5 volt positive supply is available and you need a negative voltage for op-amp or other biasing purpose, the you can generate the negative supply from the positive supply using this circuit. This circuit give same functionality with our previous 555 switching circuit, but now we use a CMOS inverter gate. Using CMOS component allow our circuit […]
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Here is a schematic diagram of electret microphone pre-amplifier using LMV721 op-amp. because the LMV721 has low noise and low power features, it would be an ideal choice for battery powered microphone preamplifier. The LMV721 is connected as an inverting amplifier. Resistors, R1 =R2 = 4.7k, sets the reference at mid point between VCC = 3V and ground. Thus, this […]
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Balanced input has three connections, ground, positive signal, and negative signal. When we trace the signal using oscilloscope, if we take the ground as the reference, then the negative signal and the positive signal has similar shape but with inverted polarity. If we measure the signal between positive and negative output, the we have two times larger signal than what […]
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This circuit is similar to our previous tone control circuit, a bass-treble tone control circuit, but here we present the formula for design your tone control’s custom frequency response. Here is the schematic diagram and formula of the tone control circuit: Almost all op-amp type can be used, as long as they have high input impedance, much higher than the […]
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For high pass filter, this circuit is similar to low-pass filter circuit, but the position for resistors and capacitor are interchanged. Here is the circuit’s schematic and formula: Similar with low pass design guide, the resistor and capacitor should be chosen according to the formula, and the resistor value should be: Much higher than equivalent leakage resistance of the capacitor. […]
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The main features of this powerful MULTIWATT® package (a trademark of SGS-THOMSON Microelectronics), a power amplifier IC chips designed specifically for car radio application, are the high current capability (3.5A) and the capability to drive a very low impedance (down to 1.6R). Here is the schematic diagram of the standard circuit as shown in its data sheet. TDA2004 has low […]
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