I recently built my voltage regulator circuit mentioned in some previous posts. While building it, I learned some important lessons regarding DC loadi

Voltage Regulator and DC Loading

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2020-10-18 05:10:49

I recently built my voltage regulator circuit mentioned in some previous posts. While building it, I learned some important lessons regarding DC loading I hope to share below.

My circuit uses the LM338 and LM117 / 317 to scale 24V in down to 16.8V, then 9V. This circuit is for a lithium ion battery charger. As per my multiple previous posts, the battery I am dealing with is a Conformable Wearable Battery (CWB), a 16-cell 5A max galoot. My circuit aims to 1. charge the battery with 16.8V in and 2. power a display circuit at 9V.

The main problems to this circuit include loading. A load is the device that uses the voltage in my circuit. Here, it is the arduino / battery combination. This circuit is especially complex, as the arduino has an onboard voltage/current regulator and accepts any input from 9-12V. Similarly, the battery has a capacity of 16.8V able to be discharged while charging.

Some engineering considerations I made were the transient response of the circuit. I included some diodes and capacitors to bleed current. If there was a large surge in current (as I expect in my specific application), I want the circuit to be protected. Below is a snapshot of my simulated transient response; it bleeds off excess voltage.

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