There are series connection and parallel connection as a method of connecting multiple switching power supplies.
If you want to increase the voltage, connect them in series, and if you want to increase the current value, connect them in parallel.
The following shows how to connect the power supplies in series.
* Actually, a diode may be inserted, but here it is explained by omitting the diode for easy understanding.
Series connection
Increase output voltage
Chokuretsu(in japanese) connection is also called ‘series connection’. Connect as above.
In the above example, if two 48V1A (48W) power supplies are connected in series, it will be 96V1A.
The voltage becomes 96V and the current value does not change at 1A.
Is it possible to connect power supplies of different models, that is, power supplies with different voltage and current values, in series?
Output without using the same model. Different voltage and current values are okay.
For example, if different power supplies of 12V1A and 24V2A are connected in series, it will be 36V1A.
The total voltage value is the smaller current value.
The power supply voltage and current for series operation can be connected differently. Theoretically, you can connect as many units as you like, but usually it is about 2 to 3 units. If you connect a lot, the voltage will increase and safety problems will arise. Please be careful.
Used for plus / minus (±) output
You may want to use the power supply with plus or minus. operational amplifier and AD converters have positive and negative inputs.
For example, if you need an output of (+ 12V-12V) or (+ 15V-15V), first look for a ± 12V or ± 15V power supply. If you don’t find it, use two single-output power supplies.
The connection method is as follows.
Parallel connection
Connect in parallel when the output current is insufficient.
The output voltage does not change.
Also, not all switching power supplies can be operated in parallel.
It is a condition that parallel operation is described as “possible” in the specifications.
How to connect in parallel.
Up to 5 units can be operated in parallel.
Adjust the output voltage within 1%. If they do not match, the current will concentrate on the power supply with the highest voltage.
Use the same material, thickness, and length for the load line. If different wires are used, the voltage drop will be different and the voltage value at the load terminal will be different. Normally, it’s not enough to worry about …
Also, some models have a built-in current balance function (PC terminal), so connect them. By connecting the PC terminal, the current is automatically balanced, so only one unit will operate at full load and the other unit will not operate at low load.
Use 80% or less of the rated current per unit, and reduce the overcurrent protection to 100% of the rated current value.
Summary
Series / parallel connection is not difficult.
I have summarized the points that you should be careful about.
