0-40V 20A Variable Power Supply DC with Battery Charging Auto Cut Off

 

0-40V 20A Variable Power Supply DC with Battery Charging Auto Cut Off

Using a step-down module, a 12V 30A relay, and a 30V DC input, a variable power supply with a 0-30V and 10A output and an auto-cut-off feature for 12V battery charging is designed. Here is a thorough manual for accomplishing this:

Components Required:

1. 30V 10A DC Input Source: This could be an adapter or a 30V DC power supply. 

2. A high-current step-down module (buck converter) that can handle 10A and can step down from 30V to 0-30V. 

3. 12V-30A Relay: For the auto cut-off feature when charging a 12V battery.

4. Mini Step Down Module for Cooling fan and DC Volt Meter.

5. 30v 10A DC Volt Meter

6. NPN Transistor BC547

7. Diode 3-6A

8. Resistor 10k & 1k

9.Pot 10k

10. LED 5mm

Step-by-Step Design:

1. Power Input:

The step-down module's input terminals should be connected to the 30V 3-10A DC input.

2. Step-Down Module:

The step-down (buck) converter will lessen the 30V contribution to a variable result of 0-30V. Check to see that the module can handle at least 10A of output current. Set the output voltage range you want by adjusting the module.

**Circuit Diagram**

12V Battery Charging and Auto Cut-Off:

Connect the battery charging terminals to the power supply's output. 

Utilize a 12V 30A relay circuit to control the charging system. The relay ought to be associated so that it can separate the charging circuit when the battery arrives at full charge.

1. Auto Cut-Off Circuit: 

Using the listed components , you can design a clear-cut voltage sensing circuit for a 12V battery auto cut-off circuit. To put off the battery from experiencing a deep discharge , this circuit will disconnect the load from the battery whenever the voltage falls below a fixed threshold. This is how you can make it .

2. Relay Connections:

Connect one end of the relay pin NC to the positive terminal of the 12V battery.

Interface the opposite end of the relay coil to the collector (C) of the BC547 semiconductor.

3.Transistor and Base Resistor:

Connect a 10kΩ potentiometerthe wiper (middle pin) between the base (B) of the BC547 transistor .

Connect a 10k resistor to the first pin of the 10k pot and the relay coil pin.

Connect the other end of the potentiometer pin to the negative terminal (ground) of the battery.

4.LED Indicators:

.Connect the two LEDsto the NC of the relay and the NO of the relay with 1k resistor .

.This LED will indicate when the battery is full charged or battery low.

 .The LEDs indicate the situation with the transfer. The load is connected and the relay is energized when the NC LED is lit. The load is disconnected and the relay is de-energized when the NO LED is lit.

 .By automatically disconnecting the load whenever the battery voltage falls below a prearranged threshold, this circuit will assist in protecting your battery from deep discharge.

**Circuit Diagram 2**

 

 Adjustment:

Set the desired battery cut-off voltage by adjusting the potentiometer.

Safety and Testing:

To effectively manage heat dissipation , install suitable heat sinks or a cooling fan on the voltage regulator and step-down module.

Include capacitors at both the input and output of the step-down module to prevent voltage spikes and ensure stable operation.

Prior to connecting the actual battery , test the entire setup with a dummy load to confirm that the auto cut-off mechanism , as well as voltage and current regulation, function correctly .

You can make a variable power supply that is adaptable , dependable , and has an integrated 12V battery charging auto cut-off feature by carefully selecting and connecting these parts.