bad inferno
New member
I have started this thread on an australian site and thought it worthwhile getting any international feedback to discuss the automation and monitoring capabilities of an aquarium. It is not intended to be another "œcontroller" thread however what devices are available to be controlled. As we get more 24VDC supply equipment i.e. pumps / lights etc the realization of control is a lot easier and does not rely on switching mains voltages. The other aspect is that I am over having to deal with a soldering iron so whatever devices are available which doesn't need circuit boards and components will in the long run provide a more reliable system that can be easily fault found if something goes wrong. I have been involved in industrial automation for 30 years.
If anybody has any devices they have found useful please contribute.
Automation Objectives:
I was planning on describing my current build with relation to the following:
A- Light & Position Control -Done
B- Sump pump flow monitoring and flow rate control. (Tunze)
Tank and Ambient Temperature inputs
Cooling fan control -Done
ATO and reservior level moniroing
Semi automatic water change
2 Part Dosing control
Conductivity & pH Inputs
DT power head controls.
Control unit
Web based monitoring and Web development for an iPad
A - Light & Position Control
The tank lighting will be automated thus to enable the light fixture to be raised or lowered. The light being suspended above the tank provides a "œmodern" look to the rimless design whilst not having wires hanging from the ceiling.
Benefits:
1. The light can be raised for maintenance ;
2. The light intensity can be changed by changing the distance the light is away from the water surface ;
3. Extending the light >150mm allows cooling fan to blow across the water surface
An 1200mm ATI 6 x 54W T5 fixture is suspended over the tank. The support frame is made out of 1" square aluminium tube and is fixed to the back of the cabinet via heavy duty rails that slide up/down. The frame is fitted with a 300mm stroke, 50kg, 12VDC linear actuator which allows the light to be raised or lowered up to a maximum of 300mm. The actuator has internal limit switches so you simply apply 12VDC and it extends, reversing the voltage enables the actuator to travel down. A feature of the frame is that on the vertical supports three 24VDC fans are fitted. These cannot normally be seen if the light is in its lowered position as the fans are behind the back of the tank. However if raised 150mm the fans will be exposed and can be powered to blow across the surface of the water.
Control:
1. The lights will simply use two light timers to turn them on/off at predetermined times. One cable has 2 tubes the other has 4 tubes, thus light intensity can be controlled by what lights are on and the position of the unit relative to the water surface. Dimmable T5 light fixtures are difficult to locate in Australia and did not want to import anything that has not got Australian approvals.
2.The actuator needs two outputs from a control unit. One to apply power the other to reverse the direction of the power. To reverse the polarity of the signal to the actuator you will need a DPDT relay.
3.As I want to be able to simulate different light intensities the light needs to be positioned at predetermined heights. To do this requires the control unit to know where the light is currently positioned. A 400mm linear potentiometer is used to measure the position of the light. The potentiometer (20k ohm ) has 5VDC applied across it and the wiper arm connected to an ADC input of the control unit. The potentiometer wiper is magnetically coupled to the frame. i.e. The 400mm long potentiometer is fixed to the rear of the cabinet in close proximity to the light frame. A small magnet is fixed to the moving frame, as the frame moves up / down the magnet moves the internal wiper of the potentiometer. The magnet needs to be <4 mm away from the potentiometer. As the potentiometer is sealed occasional water splashes should not effect it.
4.Cooling fans are powered by 24VDC. If tank temperature increases the control unit will raise the lights 150mm exposing the fans to the water surface and apply power to the cooling fans. The power to the fans will be via 24VDC pulse width modulation, PWM. Thus fan speed can be controlled depending on the tank / ambient temperatures. PWM (Fan Speed) is not proportional to the tank temperature however simply uses three speeds, Low Med and High depending on temperature setpoints.
Equipment:
Actuator -Model S200 http://www.linearactuatorsaustralia.com/c/253443/1/s200---50kg-force-ip65.html
Potentiometer "“MagentoPot http://www.spectrasymbol.com/magnetopots
Notes
If you did not have a controller you can simply wire a three way switch (centre off) DPDT and have manual control of up/down. When power is off the actuator obviously holds its position.
Rails can be purchased at various lengths and the best I have found is the Dandenong Plyboard Distributor. These rails are the ones with ball bearings and steel telescopic slides, real heavy duty and was <$30.00 for two.
These pics may assist in understanding which is from my smaller nano
Normal Position..............................Extended Position...........................Rear View Fully extended
B- Measuring Sump Return Flow
Measuring the sump return flow to the DT tank be achieved using a flowmeter. Although flowmeters can be expensive there are some moderately priced units available. The trick is how to get this flow measurement into a controller. The flow meters available either have a pulse output or an analog 0-10VDC or 4-20mA. I will be using a pulse output as the costs of the flowmeter is reduced. The model I selected is a "œpaddle" wheel flowmeter where there is a small magnet on each of the paddle wheel ends. A pickup contact is mounted in the body of the flowmeter thus every time the paddle passes the switch it activates, thus equating to pulses per litre. This flowmeter is ranged 0-20gpm (75 l/m or 4500 l/hr). It only has ½" ports so there will be a pressure drop across the flowmeter which will limit the flow back to the DT. The construction of this style of flowmeter does minimise the pressure drop.
Benefits:
1. Monitoring the flow over time will provide indication of pump efficiency and /or time for a tube clean.
2. Remote monitoring the flow when away from the house is my No1 reason
3. Having the new electronic style 24VDC pumps that have variable flow rates allows you to adjust the pump output to match your requirements.
4. You could easily increase the level of automation and set a required flowrate within the controller and let a controller adjust the pump output. The electronic style pumps use an analog signal to adjust the flowrate.
5. If you do not directly control the sump pump if the flowmeter were to fail for whatever reason there is no impact to operation.
This style of flowmeter is probably best connected to a DIY style controller as it uses pulse inputs which the controller would have to count. This is generally a standard feature on microprocessors.
Operation:
I have got the flowmeter and just waiting for the pump to arrive. I will setup a test environment and review the pumps performance with the flowmeter installed and without. I still need to verify the pressure drop across the meter does not adversely effects the max flow rate. In my case I am only looking for a ~1500 l/hr sump return rate as my tank is <350 litres. The pump capacity is variable 1000-3000 l/hr
Equipment:
If anybody has any devices they have found useful please contribute.
Automation Objectives:
I was planning on describing my current build with relation to the following:
A- Light & Position Control -Done
B- Sump pump flow monitoring and flow rate control. (Tunze)
Tank and Ambient Temperature inputs
Cooling fan control -Done
ATO and reservior level moniroing
Semi automatic water change
2 Part Dosing control
Conductivity & pH Inputs
DT power head controls.
Control unit
Web based monitoring and Web development for an iPad
A - Light & Position Control
The tank lighting will be automated thus to enable the light fixture to be raised or lowered. The light being suspended above the tank provides a "œmodern" look to the rimless design whilst not having wires hanging from the ceiling.
Benefits:
1. The light can be raised for maintenance ;
2. The light intensity can be changed by changing the distance the light is away from the water surface ;
3. Extending the light >150mm allows cooling fan to blow across the water surface
An 1200mm ATI 6 x 54W T5 fixture is suspended over the tank. The support frame is made out of 1" square aluminium tube and is fixed to the back of the cabinet via heavy duty rails that slide up/down. The frame is fitted with a 300mm stroke, 50kg, 12VDC linear actuator which allows the light to be raised or lowered up to a maximum of 300mm. The actuator has internal limit switches so you simply apply 12VDC and it extends, reversing the voltage enables the actuator to travel down. A feature of the frame is that on the vertical supports three 24VDC fans are fitted. These cannot normally be seen if the light is in its lowered position as the fans are behind the back of the tank. However if raised 150mm the fans will be exposed and can be powered to blow across the surface of the water.
Control:
1. The lights will simply use two light timers to turn them on/off at predetermined times. One cable has 2 tubes the other has 4 tubes, thus light intensity can be controlled by what lights are on and the position of the unit relative to the water surface. Dimmable T5 light fixtures are difficult to locate in Australia and did not want to import anything that has not got Australian approvals.
2.The actuator needs two outputs from a control unit. One to apply power the other to reverse the direction of the power. To reverse the polarity of the signal to the actuator you will need a DPDT relay.
3.As I want to be able to simulate different light intensities the light needs to be positioned at predetermined heights. To do this requires the control unit to know where the light is currently positioned. A 400mm linear potentiometer is used to measure the position of the light. The potentiometer (20k ohm ) has 5VDC applied across it and the wiper arm connected to an ADC input of the control unit. The potentiometer wiper is magnetically coupled to the frame. i.e. The 400mm long potentiometer is fixed to the rear of the cabinet in close proximity to the light frame. A small magnet is fixed to the moving frame, as the frame moves up / down the magnet moves the internal wiper of the potentiometer. The magnet needs to be <4 mm away from the potentiometer. As the potentiometer is sealed occasional water splashes should not effect it.
4.Cooling fans are powered by 24VDC. If tank temperature increases the control unit will raise the lights 150mm exposing the fans to the water surface and apply power to the cooling fans. The power to the fans will be via 24VDC pulse width modulation, PWM. Thus fan speed can be controlled depending on the tank / ambient temperatures. PWM (Fan Speed) is not proportional to the tank temperature however simply uses three speeds, Low Med and High depending on temperature setpoints.
Equipment:
Actuator -Model S200 http://www.linearactuatorsaustralia.com/c/253443/1/s200---50kg-force-ip65.html
Potentiometer "“MagentoPot http://www.spectrasymbol.com/magnetopots
Notes
If you did not have a controller you can simply wire a three way switch (centre off) DPDT and have manual control of up/down. When power is off the actuator obviously holds its position.
Rails can be purchased at various lengths and the best I have found is the Dandenong Plyboard Distributor. These rails are the ones with ball bearings and steel telescopic slides, real heavy duty and was <$30.00 for two.
These pics may assist in understanding which is from my smaller nano
Normal Position..............................Extended Position...........................Rear View Fully extended
B- Measuring Sump Return Flow
Measuring the sump return flow to the DT tank be achieved using a flowmeter. Although flowmeters can be expensive there are some moderately priced units available. The trick is how to get this flow measurement into a controller. The flow meters available either have a pulse output or an analog 0-10VDC or 4-20mA. I will be using a pulse output as the costs of the flowmeter is reduced. The model I selected is a "œpaddle" wheel flowmeter where there is a small magnet on each of the paddle wheel ends. A pickup contact is mounted in the body of the flowmeter thus every time the paddle passes the switch it activates, thus equating to pulses per litre. This flowmeter is ranged 0-20gpm (75 l/m or 4500 l/hr). It only has ½" ports so there will be a pressure drop across the flowmeter which will limit the flow back to the DT. The construction of this style of flowmeter does minimise the pressure drop.
Benefits:
1. Monitoring the flow over time will provide indication of pump efficiency and /or time for a tube clean.
2. Remote monitoring the flow when away from the house is my No1 reason
3. Having the new electronic style 24VDC pumps that have variable flow rates allows you to adjust the pump output to match your requirements.
4. You could easily increase the level of automation and set a required flowrate within the controller and let a controller adjust the pump output. The electronic style pumps use an analog signal to adjust the flowrate.
5. If you do not directly control the sump pump if the flowmeter were to fail for whatever reason there is no impact to operation.
This style of flowmeter is probably best connected to a DIY style controller as it uses pulse inputs which the controller would have to count. This is generally a standard feature on microprocessors.
Operation:
I have got the flowmeter and just waiting for the pump to arrive. I will setup a test environment and review the pumps performance with the flowmeter installed and without. I still need to verify the pressure drop across the meter does not adversely effects the max flow rate. In my case I am only looking for a ~1500 l/hr sump return rate as my tank is <350 litres. The pump capacity is variable 1000-3000 l/hr
Equipment:
