douggiestyle
New member
im missing it bean. maybe its the extra relay. but im still missing it
Auto Top off with high and low limits??
- Thread starter joedirt
- Start date
douggiestyle
New member
scratch that, i got it!
sorry again bruiseandy
sorry again bruiseandy
BeanAnimal
Premium Member
BruiseAndy's schematic is in ladder logic form. I am glad you figured it out doug. I didnt explain it in hopes you would become enlightened after staring at it. In any case the circuit will arm when the top floats are uncovered. When the bottom float becomes uncovered it will turn the relay on. At this point the water will begin to rise, but the relay coil will stay energized even after the bottom float opens. The "latch" is then released when either top float breaks the circuit.
Bean
Bean
Stile2
New member
As for the top schematic.
Unless I am missing something huge. The arrow shows the flow of 12 v dc. So the relay will only activate when switch #2 and the safety switch are closed. Switch #1 will have no effect. The Pump will turn on when switch #2 is closed and turnoff when switch #2 is open.
As for your design, it does more than mine, it turns off the return pump if the water level gets to low. And you are using a separate relay as a failsafe, that's fine. Also lots more leds.
But in order for K1 relay to turn on, and turn on the pump, both S2 & S3 must be closed. So the pump will turn on when the lower switch closes and turn off when it opens.
Unless you are using a "single coil latching relay", which I don't think you are because the single coil latching realy that I know of (pictured below) takes a reverse current to reset. I do not see how your design does that.
In Figure 1, current flowing from pin 1 to pin 8 latches the relay in the set position, while current from pin 8 to pin 1 resets it.
Keith
Unless I am missing something huge. The arrow shows the flow of 12 v dc. So the relay will only activate when switch #2 and the safety switch are closed. Switch #1 will have no effect. The Pump will turn on when switch #2 is closed and turnoff when switch #2 is open.
As for your design, it does more than mine, it turns off the return pump if the water level gets to low. And you are using a separate relay as a failsafe, that's fine. Also lots more leds.
But in order for K1 relay to turn on, and turn on the pump, both S2 & S3 must be closed. So the pump will turn on when the lower switch closes and turn off when it opens.
Unless you are using a "single coil latching relay", which I don't think you are because the single coil latching realy that I know of (pictured below) takes a reverse current to reset. I do not see how your design does that.
In Figure 1, current flowing from pin 1 to pin 8 latches the relay in the set position, while current from pin 8 to pin 1 resets it.
Keith
BeanAnimal
Premium Member
Stile Your missing something HUGE.
Lets take the Schematic by BruiseAndy first...
Switch 2 and 3 MUST BE CLOSED for the relay coil to energize. You got this far ok. This happens when the water level is normal or below normal.
Switch 1 MUST close for current to start to flow to switch 2 and 3. This is what your missing. If you look at the current path, it goes directly to switch 1 and also splits off through one set of the NORMALY OPEN contacts of the relay. The switch has to close or the relay has to close for current to reach the coil but the relay can not close until current reaches the coil (nice catch 22 isn't it), so this leave switch 1 as the only path.
When Switch one closes, power is sent to switch 2 and 3. If they are both closed then the relay coil energizes and pulls the contacts closed. This causes the NORMALY OPEN CONTACTS TO CLOSE. Remember that the supply current is present at the common side of the NO contacts. At this point current bypasses switch one and flows directly from the common contact to the NO contact and then to swith 2 and 3 then to the coil. This is the "LATCH". I hope you see how the relay has "wraped around itself" and is now supplying current to its own coil.
The LATCH is reset when either switch 2 or 3 is opened. Switch 2 is the normal "OFF" level and switch 3 is slightly above it in case switch 2 sticks.
The Top-off portion of my schematic works exactly the same way. It is a "latching circuit" that uses the same relay for latching and current switching. Remember we are using double pole relays. My schematic is also correct and works as a latch, you will need to look at it more closely.
Latches using relays have been around long before "latching relays". This is the basic principle that operated almost every elevator ever built until just recently.
Bean
Lets take the Schematic by BruiseAndy first...
Switch 2 and 3 MUST BE CLOSED for the relay coil to energize. You got this far ok. This happens when the water level is normal or below normal.
Switch 1 MUST close for current to start to flow to switch 2 and 3. This is what your missing. If you look at the current path, it goes directly to switch 1 and also splits off through one set of the NORMALY OPEN contacts of the relay. The switch has to close or the relay has to close for current to reach the coil but the relay can not close until current reaches the coil (nice catch 22 isn't it), so this leave switch 1 as the only path.
When Switch one closes, power is sent to switch 2 and 3. If they are both closed then the relay coil energizes and pulls the contacts closed. This causes the NORMALY OPEN CONTACTS TO CLOSE. Remember that the supply current is present at the common side of the NO contacts. At this point current bypasses switch one and flows directly from the common contact to the NO contact and then to swith 2 and 3 then to the coil. This is the "LATCH". I hope you see how the relay has "wraped around itself" and is now supplying current to its own coil.
The LATCH is reset when either switch 2 or 3 is opened. Switch 2 is the normal "OFF" level and switch 3 is slightly above it in case switch 2 sticks.
The Top-off portion of my schematic works exactly the same way. It is a "latching circuit" that uses the same relay for latching and current switching. Remember we are using double pole relays. My schematic is also correct and works as a latch, you will need to look at it more closely.
Latches using relays have been around long before "latching relays". This is the basic principle that operated almost every elevator ever built until just recently.
Bean
BeanAnimal
Premium Member
I eluded to a problem with my schematic aspublished here.
I will try to explain:
The "failsafe" relay needs to be a latch as well and use 2 floats instead of a single float. Otherwise a low water condition would cause the pump and relay to oscillate. Each time the pump turned off, the wate rin the plumbing would drain and raise the float, causing the pump tp turn back on and fill the plumbing. This would result in a low water condition and turn off the pump... so and and so on until the pump burns up or enough water evaporates to break the cycle.
I hope this makes sense as well.
Bean
I will try to explain:
The "failsafe" relay needs to be a latch as well and use 2 floats instead of a single float. Otherwise a low water condition would cause the pump and relay to oscillate. Each time the pump turned off, the wate rin the plumbing would drain and raise the float, causing the pump tp turn back on and fill the plumbing. This would result in a low water condition and turn off the pump... so and and so on until the pump burns up or enough water evaporates to break the cycle.
I hope this makes sense as well.
Bean
Bean,
Good explination! I used to have a file saved telling about latching a relay that I would send out, rather than typing it over and over
Guys, it takes a bit to wrap your head around it, but once you get it, you get it.
Bean,
I have just used timers for the purpose of controlling the short cycling float cutoff- for high tank cutout and low sump cutout. I also have an alarm light that will latch in, even if the problem corrects itself and the pump starts again. This will alert you to a problem that may need looking at.
Good explination! I used to have a file saved telling about latching a relay that I would send out, rather than typing it over and over
Guys, it takes a bit to wrap your head around it, but once you get it, you get it.
Bean,
I have just used timers for the purpose of controlling the short cycling float cutoff- for high tank cutout and low sump cutout. I also have an alarm light that will latch in, even if the problem corrects itself and the pump starts again. This will alert you to a problem that may need looking at.
BeanAnimal
Premium Member
I like the timer idea as well, except in my case the DIN mount timers I have looked at cost to much and I just cant force myself to coble a non DIN unit into my design.... Sorry I have become a snob when it comes to my not yet even close to being finished panel.
I am bidding on my 24x8x6 enclsore today. I just need to find 36 ON-ON-ON DP toggle switches (I can't afford $20 each for process control switches like you and electric130).
Bean
I am bidding on my 24x8x6 enclsore today. I just need to find 36 ON-ON-ON DP toggle switches (I can't afford $20 each for process control switches like you and electric130).
Bean
BeanAnimal
Premium Member
Here is a photo or two of my sloppy equipment rack and fishroom. The rack is the nerve center of the house (1 of 2 really) and is nowhere near it's final state. I can not finish it and clean it up until I finish the tank area. The whole room is a disaster and will not be complete until the home theater is done and I have some cash to finish the automation controller and panel.
I am somewhat ashamed to post such a messy 19" rack (don't let any of my clients see it!) but I figured it may give some folks some inspiration to tinker with electronics and wiring.
I am somewhat ashamed to post such a messy 19" rack (don't let any of my clients see it!) but I figured it may give some folks some inspiration to tinker with electronics and wiring.
BeanAnimal
Premium Member
ANd yes the TOTM has a nice DIN panel... just the kind of thing we all need!
BruiseAndy
New member
Never knew a start stop switch with a high limit safety would cause two pages of discussion. I did the same thing with the TOTM panel as well H20
BeanAnimal
Premium Member
That rack holds
1) my phone system (avaya partner ACS..I sell em),
2) BNC patch panel that is capable of distributing satalite/CATV/CCTV signals to every room in the house.
3) Every room has several CAT6 runs terminated on the top panel (T658B RJ 45)
4) Every room has several cat6 runs terminated on the next panel down (USOC RJ21)
5) The Ethernet switch, VPN endpoint, (2) 5x8 multiswitches and Small UPS (for phone system and switch) and transfer switch also live here.
Why the CAT6 terminiated on RJ21? Well if we ever sell, the new home owners and phone company tech would be confused if it was all RJ45. Gotta make it simple for the rest of the world.
The rack was to house the aquarium controller, but as you can see I am out of room. The tank automation stuff will be to the left of the tank.
The home theater has an in-wall equipment rack that will be tied to this rack as well. I have about 600 feet of interduct running throughout the home theater and between the two racks. The HT rack will hold AV patch panels and eventually all of the DirectTV recievers. The video will be pumped out of one rack for all rooms and controlled via infrared transponders.
I was going to do home automation but decided against it. It's a 30x30 ranch with a finished basement. What hell am I going to automate? The tank is the only part of the house that I desire to have automated and available online.
I have a 15/2 meg Fiber internet connection and do have a small "data center" in the adjoining room (my office). It consists of about 8 computers that range from desktops to domain controllers and file/web servers.
Sorry to take this thread off topic...
Bean
1) my phone system (avaya partner ACS..I sell em),
2) BNC patch panel that is capable of distributing satalite/CATV/CCTV signals to every room in the house.
3) Every room has several CAT6 runs terminated on the top panel (T658B RJ 45)
4) Every room has several cat6 runs terminated on the next panel down (USOC RJ21)
5) The Ethernet switch, VPN endpoint, (2) 5x8 multiswitches and Small UPS (for phone system and switch) and transfer switch also live here.
Why the CAT6 terminiated on RJ21? Well if we ever sell, the new home owners and phone company tech would be confused if it was all RJ45. Gotta make it simple for the rest of the world.
The rack was to house the aquarium controller, but as you can see I am out of room. The tank automation stuff will be to the left of the tank.
The home theater has an in-wall equipment rack that will be tied to this rack as well. I have about 600 feet of interduct running throughout the home theater and between the two racks. The HT rack will hold AV patch panels and eventually all of the DirectTV recievers. The video will be pumped out of one rack for all rooms and controlled via infrared transponders.
I was going to do home automation but decided against it. It's a 30x30 ranch with a finished basement. What hell am I going to automate? The tank is the only part of the house that I desire to have automated and available online.
I have a 15/2 meg Fiber internet connection and do have a small "data center" in the adjoining room (my office). It consists of about 8 computers that range from desktops to domain controllers and file/web servers.
Sorry to take this thread off topic...
Bean
BeanAnimal
Premium Member
as you can see.... I like finger duct. I would even trade in the Mrs for a box of the stuff! So you will understand why I have replaced MRS January desktop wallpaper with the TOTM rack photo and all of it's finger duct and pretty din breakers and relays.
<a href=showthread.php?s=&postid=6691227#post6691227 target=_blank>Originally posted</a> by BeanAnimal
Here is a photo or two of my sloppy equipment rack and fishroom. The rack is the nerve center of the house (1 of 2 really) and is nowhere near it's final state. I can not finish it and clean it up until I finish the tank area. The whole room is a disaster and will not be complete until the home theater is done and I have some cash to finish the automation controller and panel.
I am somewhat ashamed to post such a messy 19" rack (don't let any of my clients see it!) but I figured it may give some folks some inspiration to tinker with electronics and wiring.
wow, ma beananimal baby,
awksome view, i think most guys like the view. talking of automation, i'm thinking of using a Siemens "LOGO" tiny PLC to do the all the bloody wiorks, do you have any suggestion? thanks in advance.
CLICK to view my tank
BeanAnimal
Premium Member
Not very familair with the LOGO stuff first hand... But I think H20ENG or beeryguy happend to be playing around with some of the LOGO stuff. I hear it is nice (but I think it is kind of expensive).
A search of the forums may yeild a bit of info.
Bean
A search of the forums may yeild a bit of info.
Bean
douggiestyle
New member
hey bean
do you intend for k1 k2 to be mechanically latched relays that must be manually set. although that may be a bad idea for k2 after a power failure.
also whats the pupose behind the diodes d1 d2 d3
ps like the diagram, cad?
do you intend for k1 k2 to be mechanically latched relays that must be manually set. although that may be a bad idea for k2 after a power failure.
also whats the pupose behind the diodes d1 d2 d3
ps like the diagram, cad?
BeanAnimal
Premium Member
K1 and K2 are standard DPDT relays. THey are set by the action of the float switches.
The diodes are for coil supression. Without going into a lot of detail, they supress the kick back that occures when the coils field colapses. You should really never wire a relay without some type of coil supression. The kick can damage anything sensative on the same conductive path of the coil. This includes the reeds in the floats switches or even the top-off pumps (that by the way have their own kick when you turn them off).
The supression diodes do slow down the action of the relay by a few ms. Other schemes can be used such as a cap, a resistor and cap, or any combination of the above and a diode. Each has pros and cons, but for our purposes the diode will do just fine.
Bean
The diodes are for coil supression. Without going into a lot of detail, they supress the kick back that occures when the coils field colapses. You should really never wire a relay without some type of coil supression. The kick can damage anything sensative on the same conductive path of the coil. This includes the reeds in the floats switches or even the top-off pumps (that by the way have their own kick when you turn them off).
The supression diodes do slow down the action of the relay by a few ms. Other schemes can be used such as a cap, a resistor and cap, or any combination of the above and a diode. Each has pros and cons, but for our purposes the diode will do just fine.
Bean
BeanAnimal
Premium Member
BTW... that schematic leaves a lot do be desired, it was posted as an example of a latching circuit. I would hope that anybody using it would make the needed modifications to overcome it's shortcomings.
I think I did the schematic in Protel and exported it as a gif... it was a long time ago! Visio is usefull for small schematics, as are a few of the big schematic capture programs that offer demo or "amature" editions for free.
Eagle PCB comes to mind, as does ExpressPCB and a few others.
I think I did the schematic in Protel and exported it as a gif... it was a long time ago! Visio is usefull for small schematics, as are a few of the big schematic capture programs that offer demo or "amature" editions for free.
Eagle PCB comes to mind, as does ExpressPCB and a few others.
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