Free electronic circuit design and schematic diagram
The schematic diagram below shows a very simple sample-and-hold circuit using the CA3140 as the readout amplifier for the memory capacitor. The CA3080A is used as both input buffer amplifier and low feed-through transmission switch. System offset nulling is provided for CA3140 via its offset nulling pins. A load simulation of 2k and 30pF is shown in the schematic , […]
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The excellent high input impedance, high slew rate, and high voltage qualities of CA3140 op-amp make it suitable for Wien-bridge sine wave oscillator. The basic circuit for Wien-bridge sine wave oscillator is shown in the figure below (the upper part). You can see the formula in the figure, when R1=R2=R, and C1=C2=C, then the formula would be a very simple […]
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Current amplifier application need very low input bias current, and CA3140 is one of suitable op-amps for this purpose. The circuit’s schematic diagram is shown in the figure below. In the circuit, low current is supplied at the input potential as the power supply to load resistor RL. When the load current is monitored by the power supply meter M, […]
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A constant-current/constant-voltage linear charger for single-cell lithium-ion (li-ion) can be constructed using only a tiny battery charger controller chip EUP8054 and a few passive components. This tiny integrated circuit chip is suitable for various portable devices. This controller chip is also compatible with USB power specification, ideal for charging the battery when the device is plugged to USB port. Here […]
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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 […]
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This LED (Light Emitiing Diode) display consist of 10 LEDs to indicate the level of an input signal. If the signal is small, only LED#1 will light, and if the signal level getting higher then you’ll se the light dot will move through LED #2, #3, #4, … and so on. When the signal input drive the dot until LED […]
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This circuit is similar to peak detector, but the the output won’t immediatelly follow the input peaking. Because the output follow the input peak slowly, averaging effect will be seen at the output. In the figure below you can see the circuit’s schematic diagram. Use 1% resistor for R1, R2, R3, and R4, and you can achieve negative and positive […]
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