Free electronic circuit design and schematic diagram
Using only transistors as the active components, we can build a simple and low cost TTL-to-RS232 level converter. It uses only two transistors as the active components. Here is the schematic diagram of the converter: You can use any small signal transistor for this RS232 converter circuit. You can see the collector of Q1 transistor is connected to TxD, and […]
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Light dimmer circuit is used to control the lamp for arbitrary brightness. This dimmer circuit work for incandescent lamp, not a fluorescent one. The dimmer circuit here work for both 110V and 220V AC. Here is the schematic diagram of the circuit: Dimmer Wiring Diagram The dimmer circuit is wired in series with the lamp, you can say the dimmer […]
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Many new computers now only has USB port, and this serial to USB adapter might be the only help for old devices that provides only RS232/COM Port. This serial adapter uses FT232 USB-RS232 converter IC from FTDI (Future Technology Devices International). The main features of this USB serial adapter chip are: 384 byte receive buffer / 128 byte transmit buffer […]
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RS485 interface gives some more benefits compared to RS232: simplicity and the robustness for long distance transfer. RS485 is simpler because it uses only two wire (or a single pair) to carry out the data in bidirectional manner, using RS232, we need 3 wires at minimum to carry the data bidirectionally. RS485 cable length can be as long as 1.2 […]
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Using a standard fluorescent tube lamp (TL), you can make your own disco light, similar to a stroboscope light. You can even use a half-broken lamp, which one side of the heating filaments has broken. This circuit use only one side heating filament inside the tube. Look at the circuit’s schematic below. Please be aware that this circuit uses high […]
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Crossover Calculator An online crossover calculator in this link is not only capable of designing 1st order crossover, but 2nd, 3rd, and 4th crossover calculation is also supported. Designing a 3 way crossover using the tool is very easy, you just need to fill the form to specify the design parameters: tweeter impedance, midrange impedance, and woover impedance, high crossover […]
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In designing small signal amplifier circuits, to achieve a specified amplifier gain we usually use opamp amplifier design to ease the setting of the gain. When the gain accuracy is not critical, we can use transistor feedback amplifier as the base of our amplifier design. Here is the schematic diagram of the transistor amplifier: Transistor Operation Without TR2, taking the […]
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