Step-down voltage regulator 300 W - 6-40 V to 1.2-36 V, 20 A

Product overview

• Switching DC-DC step-down converter for input voltages from 6 to 40 V
• Output continuously adjustable between 1.2 and 36 V
• Up to 20 A output current, maximum power 300 W
• Constant-current and constant-voltage modes with automatic switching
• Output voltage and current limit independently adjustable via precision trimmers
• Screw terminals for input and output, slide switch for safe control
• Integrated heatsinks on both sides of the circuit board

Product description

This step-down voltage regulator converts higher DC voltages into lower ones using a switched operating principle instead of simple linear losses. An inductor and a power transistor transfer energy in pulses, resulting in significantly lower heat loss than with linear regulators. This enables high currents of up to 20 A with a relatively compact heatsink.

Both parameters, the output voltage and maximum output current, can be adjusted independently using two trimmers. The module automatically switches between constant-voltage and constant-current operation, depending on which limit is reached first. This makes it ideal for charging batteries according to the usual profile: constant current up to the target voltage, followed by constant voltage until charging is stopped. The module is also suitable as a current source for LED strips or for generating adjustable supply voltages.

The input and output use screw terminals that also provide reliable connections with thicker cables. A slide switch enables quick switching off and on without disconnecting cables.

The maximum values of 20 A and 300 W can only be achieved with effective cooling. During continuous operation, the module should be operated well below these limits. At higher continuous loads, additional active cooling with a fan is required, as the existing heatsinks alone cannot dissipate the heat continuously at full load. Intended for prototypes and laboratory setups operated under appropriately controlled temperature conditions.

Safety information

At currents above 10 A, the input and output areas can become significantly hot; avoid contact with hot surfaces and ensure sufficient air circulation. The module is intended exclusively for prototypes and test and development purposes and is not suitable for installation in the mains power system. Work on or near electrical installations must be carried out by qualified electricians; if in doubt, consult a qualified electrician before commissioning.

Scope of delivery

• 1x DC-DC Step-Down Module - 300W, 20A, 6-40V to 1.2-36V