42-60V 0-38A ZHONHEN APR48-3G charger PSU modification voltage and current adjustment

BH4SKM

1 mW
Joined
Mar 2, 2020
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Hello everyone, I am an electronics enthusiast in China. I also like to play electric bicycles and yearn for a free life. However, it is illegal to modify electric bicycles in China. We cannot even discuss this topic. China's electric bicycle modification forum has been forced to close, so I can only come here to discuss and share various issues about electric bicycles with you, thank you all.

After careful observation, I found that the ZHONHEN APR48-3G is simpler and easier to modify and adjust the voltage and current than the Eaton APR48. The advantages are: ① The shell has a screw structure, while the Eaton shell has a rivet structure. ②The voltage adjustment resistor is on the outside of the control board. ③There is space to install a voltmeter. ④There is space to install the current adjustment potentiometer. ⑤12V power supply with voltmeter. ⑥ Both voltage and current can be adjusted linearly. ⑦ There are two channels of overvoltage protection. ⑧There are 7 filter capacitors. After simple modification, it can operate 42V-60V, 0-38A. If the second overvoltage protection circuit is connected in series with a 12V regulator tube, the output voltage can be increased to 70V (the original capacitor has a voltage resistance of 63V, and the output filter capacitor needs to be replaced). If you want to increase it to 100V, you need to remove the transformer and put the second The secondary coil of the circuit is changed from parallel to series. The YouTube tutorial I posted, 42-60V, 0-38A, you need to prepare a voltage and ammeter (0-100V50A) shunt 50A75mV, a 20K trimmer resistor (note to adjust it to 10K before installation, otherwise it will shut down inexplicably and you will be at a loss) ), a 1.5K linear potentiometer, some insulating tubes, etc. My video tutorial is very complicated, but the modification is actually very simple and easy.

The main structure of Eaton APR48 and Zhongheng APR48 are the same, but there are big differences in details. I think Zhongheng APR48 is an optimized version of Eaton APR48. The modification of Eaton APR48 is difficult, so I chose Zhongheng APR48 for modification. It's very simple. When changing the voltage regulation, remove R281 (10K resistor) and replace it with a 20K trimmer resistor. To adjust the current, you only need to cut off a current feedback line and connect a 1.5K potentiometer in series. Yes, it is that easy.
 

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Zhongheng APR48-3G is very cheap in China's flea market, only 60 RMB ($9) each. A few years ago, I bought 5 units ($55) for 80RMB ($11), and the modification was very successful.
 

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Very nice mod :)
Do you know how to get the current control on the Eaton APR48 too?
Hello, the main structure of Eaton APR48 and Zhongheng APR48 are the same, but there are big differences in details. I think Zhongheng APR48 is an optimized version of Eaton APR48. It is difficult to modify the Eaton APR48, so I chose Zhongheng APR48, the modification is very simple. When changing the voltage regulation, remove R281 (10K resistor) and replace it with a 20K trimmer resistor. To adjust the current, you only need to cut off a current feedback line and connect a 1.5K potentiometer in series. Yes, it is that simple.
 
I already have a few eaton APR48 that I have done the voltage mod on that is presented on this forum, but I am looking for adjustable current too. I dont have the electronics know how to figure it out myself unfortunately.

Those Zongheng seems rare outside of China, I find some expensive NPR48 on ebay.
 
Very nice. Yeah I have seen the mod in some forums, even chinese one, but maybe not exactly this mod. I didn't know they were so zealous over there but I get the point. I have some inside knowledge.

I've had the 0-100v when it came around many years ago with Huawei RG4850 (RG4850xx) as a base for the mod. My version is 0-32,5A. I repaired it once when my fuse burnt away so I had to replace the XT90 output connector and the tricky stuff there.

Now I'm working on a ev- charger with a relay and a set 520ohm resistor and my output voltage of this 72v 8a charger is 88v but I want to lower it so I'm thinking of how to do it. If you have any idea please let met know as I'm learning about what does what on a charger as well as staying safe to not touch something in the wrong way and die.
 
很不错。是的,我在一些论坛上看到过这个模组,甚至是中文的,但也许不完全是这个模组。我不知道他们在那里如此热心,但我明白了。我有一些内幕知识。

很多年前,当它以华为 RG4850 (RG4850xx) 作为主机的基础时,我就使用过 0-100v。我的版本是0-32,5A。当我的保险丝烧坏时,我修理过一次,所以我不得不更换 XT90 输出连接器和那里棘手的东西。

现在我正在开发一个带有继电器和一组 520 欧姆电阻的 ev 充电器,我的这个 72v 8a 充电器的输出电压是 88v,但我想降低它,所以我正在考虑如何做到这一点。如果您有任何想法,请告诉我,因为我正在学习充电器的作用以及保持安全,以免以错误的方式触摸某些东西并导致死亡。
You must first understand which model of the switching power supply IC is. If it is TL494, then you are lucky, because it is very easy to change the voltage of TL494. I posted the 24V MEAN WELL modification tutorial on YouTube. I successfully modified it to 0-30V. If you only reduce part of the voltage, it is easier (no need to install a 12V auxiliary power supply)
 
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