Simple 5V/5A regulator with voltage monitor - RC Groups
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Apr 22, 2007, 11:59 AM
Hi Wattage Electrics - Cool
Rad Racer's Avatar

Simple 5V/5A regulator with voltage monitor

Here's a simple 5volt / 5amp, LDO regulator circuit with a twist.

Before we start.....I do know linear regulators are not as effiecent as switching type regulators.....but I decided to go linear anyway, and keep the design simple. Heck, you will get plenty of flights in between charges

This regulator circuit was designed to use 2 or 3 cell lipo packs to power the receiver/servos. It's integrated voltage monitor circuit, provides real-time feedback (LED's) giving you the charge status of your pack, so you know when it's time to recharge, hopefully preventing you from over discharging your LiPo.

I use one in my "electrified" H9 P47 works great!

Here's how it works:

Basically, the LM1084 regulator provides a clean 5 volts to your receiver, servos and PIC voltage monitor circuit. A PIC microcontroller (via voltage divider) measures the level of the pack and displays the results on 1 of 4 status LED's. The software is designed to "auto detect" the cells in your Lipo pack, so no needed to worry about manual switch settings. On powerup, the software will confirm (via LED flash's) that it has detected your battery pack correctly.

The monitor has 3 green and 1 red LED's. The green LED's indicate Full, med, and low charge. The red triggers at 9v for a 3-cell pack and 6.6v for a 2-cell pack.

Using surface mount components, mine comes in at 7 grams. For ease of construction, you can use thru-hole components...they don't add much weight.

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Apr 22, 2007, 12:26 PM
Hi Wattage Electrics - Cool
Rad Racer's Avatar
Here's the schematic and board layout for anyone that might be interested in building one for themselves. Sorry about the napkin drawing....hopefully it's clear enough for everyone.
Apr 22, 2007, 12:40 PM
Hi Wattage Electrics - Cool
Rad Racer's Avatar
The hex code for the voltage monitor circuit above. This is written for the PIC12F675 controller.
Apr 22, 2007, 10:27 PM
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podavis's Avatar
Any chance of posting an .asm file? I've been learning pic-speak and need the practice.
I like the drawings, simple is good.
Apr 23, 2007, 01:33 PM
Hi Wattage Electrics - Cool
Rad Racer's Avatar
I had not planned on releasing the source code for this project, as it is part of a larger project currently in the works. I can certainly explain the project in more detail...perhaps that will help you get started with your pic programming.

If interested, I do have some PCB's and programmed pics.....either or both are available at a resonable cost.

Thanks for your interest in this project.

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