Low Voltage Disconnect used as Charge Controller

Posted on January 31, 2015 by neil

Pictured below is our 12V Programmable Low Voltage Disconnect with Display as sold in the REUK Shop. The product is designed to prevent batteries from being overly discharged and damaged by automatically turning the load devices on or off depending on the measured battery voltage.

We recently made a few modifications to this design of this LVD for a customer to enable this device to be used as a charge controller; turning it into a high voltage disconnect.

There is a battery bank and a generator which is used to charge it. We replaced the standard 12V output on the low voltage disconnect board with a relay so that it could switch the generator on and off automatically. We then changed the code on the Arduino microcontroller so that the relay would open (turning off the generator) if the battery bank voltage exceeded a user set value, and would then close the relay again (turning on the generator) when the battery voltage fell below a second user set value. By doing this the batteries are well cared for – never being overcharged, and never becoming overly depleted.

If you require a low voltage disconnect or a modification made to one of our LVD products such as this charge controller, please email neil@reuk.co.uk with details of your requirements.

Programmable Low Voltage Automatic Battery Charger

Posted on January 29, 2015 by neil

Our Mini Programmable 12V Low Voltage Disconnect (LVD) is designed to disconnect loads from batteries when the battery voltage falls below a user set value, and then reconnect the loads when the battery voltage gets back above a second (higher) user set value.

With a few modifications to the code on the microcontroller of this device it can also be reconfigured as a low voltage connect – a device which will (typically) be used to connect a charger to the battery when its voltage gets low, and then disconnect it when the battery voltage gets higher after charging.

Today we made such a low voltage connect for a customer with a semi off grid garden office, a PV solar charged battery bank, and a selection of lights, 5V chargers, and other low voltage DC loads to be powered. He has a mains powered 5A bench power supply which he wanted to automatically connect to the battery bank via a solid state relay (SSR) when the battery bank voltage fell due to a period of poor solar generation (English weather) or from using a lot of battery power.

With our low voltage connect controlling the SSR, the battery bank will never be able to get overly-depleted and battery power will always be available to power the garden office.

If you need any kind of low voltage disconnect, low voltage connect, or high voltage disconnect etc, please email neil@reuk.co.uk with details of your requirements.

Solar Water Heating Pump Controller with Maximum Pump Run Time

Posted on January 26, 2015 by neil

Our 2014 Solar Water Heating Pump Controller with LCD is one of our best selling products. We recently receive an original request for a modified version of this controller for use with a solar heated swimming pool in France. This particular system has a 12V powered submersible pump which has a maximum duty cycle of 15 minutes – i.e. if the pump is run for longer than 15 minutes continuously it could be damaged.

In general the pump in such a system will not run for that long, but it is likely to happen from time to time – particularly in the spring when the pool is cool, but the panel is getting well heated in the middle of the day. Therefore something needs to be added to the controller to protect it from this eventuality. Also, this controller has a manual override to force the pump to run, and this could be forgotten and left on for hours burning out a vulnerable pump if there is no protection.

Pictured above is controller board we made – this time with a relay to switch the current to the pump rather than the standard MOSFET 2A 12V output. We also added waterproof temperature sensors to make the device suitable for pool use.

To the standard user programming options we added the ability to set the maximum number of minutes the pump may run continuously, and the number of minutes the pump must then be left off before it can be turned on again. These values can be set to anything from 1-60 minutes each to give flexibility should the pump need to be changed in the future. The user of this controller intends to set a 12 minute maximum run time and a 3 minute forced off time. (As the 2014 controller is Arduino based, we used the millis() function to keep track of time while the pump is running).

If you need any kind of solar water heating pump controller, please email details of your exact requirements to neil@reuk.co.uk.

Mains Powered Fan Controller for Art Project

Posted on January 22, 2015 by neil

We are often requested to make timers and other electronic controllers for use within art projects and art installations. In general these are sold to people who have no electronics knowledge, and so we have to make them as simple to use as possible with pre-wiring of any mains powered devices etc.

Pictured below is one such timer we recently made designed to control a fan which in turn moves fabric as part of an art installation.

This device is designed to run a mains powered fan – 15 seconds ON 15 seconds OFF in a repeating cycle. This fan (a bathroom extractor fan) had already been wired for the artist with a standard plug by an electrician.

So the the electrician was not required further, we pre-wired this controller with a standard plug on the input side and a standard socket on the output side to which the fan could be plugged in. All other wiring is located on the circuit board which is all sealed away in a black box for safety. The whole things is powered by an external 12VDC plug in power supply.

Every 15 seconds the on board relay is opened or closed which in turn either connects or disconnects the power from the socket turning the fan off or on as required.

If you need any type of timer or other controller for an art project, please contact neil@reuk.co.uk with details of your exact requirements.

Poultry House Door Controller with Digital Timer

Posted on January 14, 2015 by neil

One of our most popular products is this Dawn Dusk Automatic Hen House Door Controller. This device automatically detects dawn and dusk using a light detector calibrated by the user and runs a motor one way in the morning to open a hen house door, and the other way in the evening to close the door. Roller limit switches act to ensure that the door fully opens and closes without over or under running.

Pictured below is a alternative but similar device which uses a programmable digital timer to set the times of day that the door is to open and close.

When the timer turns on, the motor runs to open the door until the upper roller switch closes. Then when the timer turns off, the motor runs to close the door until the lower roller switch closes.

The advantage of using a timer is that the door can be set to open later on weekends for example to reduce noise from the birds, and the exact times the door is to be opened and closed can be set independently of the level of daylight (and therefore of the weather). The disadvantage is that the timings have to be changed every few weeks as the seasons change and the days get longer and shorter.

If you need any type of automatic poultry house door controller, please email neil@reuk.co.uk with details of your exact requirements.

Poultry Lighting Controller with LVD and Display

Posted on January 8, 2015 by neil

We have been selling a selection of poultry lighting controllers for many years now – devices designed to stimulate egg production in the winter months using artificial light at dusk and/or before dawn to trick the birds.

Pictured below is a bespoke lighting controller we recently made for a more advanced poultry lighting controller including a double voltage regulator so that more LED bulbs can be used in a large poultry house, an automatic low voltage disconnect, and an LCD display to show system status and for use in setting up the system.

This device will automatically detect dusk and turn on the lights in the poultry house for a user-programmable number of hours (including zero). The lights then turn off (if they had been on) and remain off for 9 hours to give the birds a 9 hour sleep and a 15 hour day for maximum egg production. The lights then turn on in the early morning and remain on until dawn when natural light is bright enough to take over.

Dawn and dusk are detected using a light dependent resistor, and the user can calibrate the exact light level which they consider to be at the threshold between day and dusk, and between night and dawn.

To protect the battery from being run too low of charge and being damaged, the user can programme into the device three trigger voltages: a voltage below which the on board red LED will turn on as an early warning, a voltage below which the output (to the lights if on) will be turned off, and a voltage above which the low voltage disconnect will be cancelled restoring the outputs automatically when the battery is recharged.

There is also a manual override option which enables the lights to be turned on manually at any time (low voltage disconnect permitting) when the poultry house needs to be cleaned or the eggs to be collected etc.

At all times the backlit LCD display shows the status of the system including the currently measured battery voltage, whether the LVD is engaged, whether the outputs are on or off, the current position in the cycle DAY, DUSK, SLEEP, PREDAWN, DAWN (or MANUAL when the override is active), and the currently measured light level relative to the user set threshold.

If you need any kind of poultry lighting solution, please email neil@reuk.co.uk with details of your exact requirements and we should be able to put something suitable together for you.

Rainwater Toilet Flush Pump Controller with Overrun Protection

Posted on January 2, 2015 by neil

We make a wide selection of rainwater toilet flush pump controllers for domestic use, and pictured below is another of these.

This particular controller is designed to be used where there is a very large amount of rainwater storage and a relatively small header tank. In this scenario, if the float switch which detects whether the header tank is full were ever to fail or get jammed with debris etc, 1000’s of litres of stored rainwater could be pumped out through the header tank overflow and lost.

In this controller, the user can programme in a maximum pump running time. If the pump ever runs for longer than that time, it will automatically be turned off, and will not turn on again until there has been manual intervention from the user (checking over everything and resetting the controller).

In standard operation, the controller simply checks the status of the header tank float switch located just below the tank overflow outlet, and shows this status with an LED indicator. Once every four hours, the controller tops up the header tank by turning on the pump and running it until the header tank is detected to to be full.

If you need any kind of pump controller, please contact neil@reuk.co.uk with details of your exact requirements.

REUK.co.uk

The Renewable Energy Website

Monthly Archives: January 2015