DC step up module problem

Thread Starter

meowsoft

Joined Feb 27, 2021
607
Can I damage my DC step up module if output terminal is connected together with another power sources in same step up output voltage ?, Is there any problem if DC DC step up output is also get input from power sources with same voltage ?
Example : Connect together two power sources from 36v DC power supply and 12v batter with 12v/36v DC DC Step up
Note : DC DC step up module is non isolated module
 

Thread Starter

meowsoft

Joined Feb 27, 2021
607
Parallel, 36v DC from power supply and 36v from 12v battery with 12v/36v step up connected in parallel, to 36v DC load
Is there any problem ?
 

dcbingaman

Joined Jun 30, 2021
1,065
As a general rule, no you cannot connect two DC power supply outputs in parallel. The DC voltages are not exactly the same. Some power supplies, (not all) allow for a second power supply in 'Slave Mode' but this requires the two power supplies to communicate via a link. One is set as the master and the other as the slave. In this case you can connect two power supplies in parallel. You can always connect two power supplies in series with no issues except the current will be limited by the power supply with the lower current limit.
Any voltage regulated power supply is basically a closed PID control loop where the control variable is voltage. Because it is a closed PID control loop, connecting two in parallel will typically result in the two power supplies, fighting against each other, current will flow between them and possibly destabilize the PID control loop causing it to go into oscillations. This can possibly destroy one or both power supplies.
 
Last edited:

Beau Schwabe

Joined Nov 7, 2019
155
It still depends on the internals of the power supply and if it is stated from the manufacturer that you can run them in Parallel. On a large industrial project we dispersed twenty 10Amp 48Volt power supplies evenly spaced across a 150 foot track ( Think roller coaster with brush tracks to deliver power to each "car" on the track. ). A dedicated 100 Amp service panel supplied power to all twenty power supplies.
 

dcbingaman

Joined Jun 30, 2021
1,065
It still depends on the internals of the power supply and if it is stated from the manufacturer that you can run them in Parallel. On a large industrial project we dispersed twenty 10Amp 48Volt power supplies evenly spaced across a 150 foot track ( Think roller coaster with brush tracks to deliver power to each "car" on the track. ). A dedicated 100 Amp service panel supplied power to all twenty power supplies.
True enough. It needs to state explicitly in the power supply datasheet that you can do this. Most power supplies I have ran across do not support this ability.
 

Thread Starter

meowsoft

Joined Feb 27, 2021
607
As a general rule, no you cannot connect two DC power supply outputs in parallel. The DC voltages are not exactly the same. Some power supplies, (not all) allow for a second power supply in 'Slave Mode' but this requires the two power supplies to communicate via a link. One is set as the master and the other as the slave. In this case you can connect two power supplies in parallel. You can always connect two power supplies in series with no issues except the current will be limited by the power supply with the lower current limit.
Any voltage regulated power supply is basically a closed PID control loop where the control variable is voltage. Because it is a closed PID control loop, connecting two in parallel will typically result in the two power supplies, fighting against each other, current will flow between them and possibly destabilize the PID control loop causing it to go into oscillations. This can possibly destroy one or both power supplies.
Before I was use this power supply in series and also parallel (SMPS and SMPS), but was not tested for parallel (SMPS with another brand/DIY SMPS/XL4016 based SMPS), do you think there is a problem with XL4016 module ?
 

Thread Starter

meowsoft

Joined Feb 27, 2021
607
True enough. It needs to state explicitly in the power supply datasheet that you can do this. Most power supplies I have ran across do not support this ability.
In this case the problem is XL4016, do you think that's can run parallel with SMPS ?, and protect from reverse current ?, I think battery can explode if there is reverse current, battery is 12v (stepped up to 36v with xl4016), and SMPS is 36v, also SMPS is 3x 12v in series and was used for about two years without problem, I don't have schematic for SMPS, it's generic Chinese power supply with 220v AC/50Hz input, and 10-14v DC 40a output (I use three in series, so they make 36v DC 40a output), also with short circuit and overcurrent protection
 

dcbingaman

Joined Jun 30, 2021
1,065
In this case the problem is XL4016, do you think that's can run parallel with SMPS ?, and protect from reverse current ?, I think battery can explode if there is reverse current, battery is 12v (stepped up to 36v with xl4016), and SMPS is 36v, also SMPS is 3x 12v in series and was used for about two years without problem, I don't have schematic for SMPS, it's generic Chinese power supply with 220v AC/50Hz input, and 10-14v DC 40a output (I use three in series, so they make 36v DC 40a output), also with short circuit and overcurrent protection
If you have a datasheet for the part, please provide it. I will take a look. I could not find that datasheet on a search.
 

dcbingaman

Joined Jun 30, 2021
1,065
Nice chip. Looks like it is very easy to use. Being that is has overcurrent protection built in you could probably try to put two outputs in parallel and see what happens. The datasheet does not talk about parallel operational capability. If it did support that they would probably be talking about it somewhere in the datasheet. I have a feeling it cannot, but you never know.
 
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