1URDC Home Page

 1. A board design to fit in some inexpensive Mass Produced plastic NEMA cases.
2. Separate  fuses for the Power and Microprocessor sections.
3. Another layer of transient/surge protection for the Power section.
4. A hardware change in the Temperature Compensation section that allows for smoother more precise voltage control.
5. An adjustable Equalization set-point.
6. The ablity to switch up to 6 Automotive Electromechanical Relays instead of 4 (Relay Dependant).
7. Some changes and additions to the board labels.

Introduction

These diversion controllers were brought about by there being no low cost expandable diversion controllers on the market that would maximize battery charge and life.

Months of testing and research both on these and other commercially available dump controllers, has proven that the On-Off algorithm using EMRs (ElectroMechanical Relays) in diversion/dump mode is seriously lacking. EMRs are slow (most can not be switched faster than 2 sec on, 2 sec off to prevent self destruction and contact bounce), this delay knocks the surface charge too low when switching a load on and off so that the battery cannot absorb enough energy to fully charge. This works fine however when disconnecting the charging source from the battery and letting the battery voltage drop naturally. The majority of wind and hydro generators cannot simply be disconnected from battery and allowed to free spin as this could cause them to over rev at high speeds and self destruct. Most SSRs (Solid State Relays) on the other hand can be switched at 20ms on and 20ms off or faster so as not to let the battery voltage drop too low. Thus allowing the batteries to absorb more energy, resulting in the batteries charging at a much higher rate and SOC (State Of Charge) which leads to a greatly extending battery life (batteries are the greatest consumable cost in renewable energy systems).

In the process of developing a effective charge algorithm for use with SSRs in which I call ULFAPWMA (Ultra Low Frequency Adaptive Pulse Width Modulation Algorithm). I started seeing how many features and how much protection I could add and still keep them inexpensive. Also I have tried to make these as user friendly, adaptable and expandable as possible. Basically these controllers are what I WANTED in a controller of this type and not the simple, barely adequate ones that were being offered on the market in this and higher price ranges.

The manual will probably evolve for some time so to keep cost down and prevent unnecessary waste, the latest version of this manual in PDF format is Free for DOWNLOAD HERE (just printout what you need) or a printed version is available for $3 USD from WindAndSunPower.com.

This page will continue to grow so check back for updates.

Thanks,

Jeff

  The 2-Stage works Basically the same as the conventional On/Off algorithm except that instead of the large high to low voltage discharge swings, it will hold the dump or "Float" voltage constant or steady. This allows the batteries accept a more complete charge. I used the term 2-Stage because when used with SSRs in that mode it functions as a low frequency 2-Stage PWM Diversion Controller.
  A 2-Stage charge algorithm is, Bulk and Float. A 3-Stage charge algorithm is, Bulk, Absorption and Float. I will have a model that will also be capable of 3-Stage SSR Diversion hopefully around the first of the year.
  SSRs will work in either position but for 2-Stage the switch should be in the up or the on position.