Variable Dual Lab Power Supply
The circuit utilizes the LM317 and LM337 integrated circuits, which are widely recognized as adjustable voltage regulators. The LM317 is used for positive voltage regulation, while the LM337 handles negative voltage regulation. This configuration allows for a dual-output power supply that can provide both positive and negative voltage levels, making it suitable for testing various audio amplifiers and other electronic devices.
The typical operating voltage range for the LM317 is between 1.25V to 37V, and for the LM337, it is between -1.25V to -37V, with a maximum output current of 1.5A. The output voltage can be adjusted using two external resistors, which form a voltage divider. The values of these resistors determine the output voltage according to the formula provided in the LM317 and LM337 datasheets.
To ensure stability and proper operation, it is advisable to include bypass capacitors at the input and output terminals of both regulators. A 0.1µF ceramic capacitor is typically used at the output to improve transient response, while a larger electrolytic capacitor may be added to the input to filter out any noise from the power source.
The circuit should also incorporate heat sinks for both the LM317 and LM337, as they can generate significant heat during operation, especially when the input voltage is substantially higher than the output voltage. Proper thermal management is essential to prevent overheating and ensure reliable performance.
The overall design should include a power switch and an LED indicator to show when the power supply is active. Additionally, terminal blocks or banana jacks can be used for connecting the output leads, making it easier to interface with the devices under test.
This power supply setup is particularly advantageous for audio applications, where it can be used to power operational amplifiers, preamplifiers, and other audio-related circuits. However, it is important to note that this power supply is not designed for high-current applications or continuous operation under heavy loads, as it may not provide sufficient power for demanding devices.The power supply is based on the LM317 and LM337 variable 3-terminal regulators ICs, and while it is no powerhouse, it is quite satisfactory for testing most power amps, as long as there is no speaker connected. 🔗 External reference
Related Circuits
One very important part of a tube amplifier is the power supply. It is crucial for the quality of the whole system. Especially beginners encounter problems like hum or drift that can become quite annoying. But rescue is ahead:...
A low-cost converter is capable of supplying constant AC currents up to 1 A over variable loads. The low-cost converter is designed to provide a stable output of alternating current (AC) while accommodating fluctuating load conditions. This capability is essential...
The amplifier feeding the final amplification stage operates with unstabilized voltage. The output stage, utilizing push-pull operation, exhibits significant rejection of the supply voltage. However, the earlier stages do not provide the same level of rejection, resulting in unwanted...
A Power Factor Correction (PFC) board has been obtained from an old Sun Microsystems Spark450 power supply (part number 300-1359-xx). This board contains all necessary components for a 650-watt inverter. However, the complete PFC circuit is not fully detailed...
The switching power supply, shown in the schematic, provides 12 volts, at 10 amps, maximum, using a discrete transistor regulator with an op-amp functioning as a comparator in the feedback circuit. The supply was constructed in 1984 and is...
A power supply project that operates without a traditional transformer, potentially saving costs but also presenting lethal voltages at the output terminals. This project should not be attempted by beginners due to the electric shock hazard. In the UK,...