UPS / Mains Filter for sensitive devices
It’s an add-on for my Homemade UPS
Do anyone know how to built a device that only activates a relay then the voltage go higher than +250V and lower than -220V and it mist have a indicator “LEDs” to show the current state of the mains like, example.
Relay must activate only where the “R” stands, so then the relay activates the DC source
Higher than +- 250V = Red LED “R”
Normal State in between = Green LED
Lower than +- 220V = Yellow LED “R”
Lower than +- 10V = Flashing Yellow LED “R”
Additional:
And the other stuff is, and then is higher than +- 250V it must convert it back to usable 12V DC for the inverter
And then lower than 220V it must make it also useable 12V for my Inverter for an sort of alternative Energy source then the voltages are messed up
It’s an add-on for my Homemade UPS
Do anyone know how to built a device that only activates a relay then the voltage go higher than +250V and lower than -220V and it mist have a indicator “LEDs” to show the current state of the mains like, example.
Relay must activate only where the “R” stands, so then the relay activates the DC source
Higher than +- 250V = Red LED “R”
Normal State in between = Green LED
Lower than +- 220V = Yellow LED “R”
Lower than +- 10V = Flashing Yellow LED “R”
Additional:
And the other stuff is, and then is higher than +- 250V it must convert it back to usable 12V DC for the inverter
And then lower than 220V it must make it also useable 12V for my Inverter for an sort of alternative Energy source then the voltages are messed up
>Higher than +- 250V = Red LED “R”
Normal State in between = Green LED
Lower than +- 220V = Yellow LED “R”
Lower than +- 10V = Flashing Yellow LED “R”
Probably the simplest way to do this is with a microcontroller that has a built in ADC. A small 8 or 14 pin microcontroller could be programmed to monitor the voltage using the ADC (using a voltage divider of course) and each LED would be connected to I/O pins on the Microcontroller. You would write code to monitor the ADC output and turn on or off output pins. This can be done in a software loop to make the LEDs flash. Alternatively you could use a set of voltage comparors like the LM311. You would need to use a reference voltage and configure a voltage divider so that it's output matches the reference voltage. I believe the LM311 datasheet contains example circuits for low or high voltage detection. There are also voltage monitor chips available, (I believe MAXIUM makes a bunch) but I believe the majority of these chips are surface mount and are geared towards battery management for portable devices. But using a voltage comparor or monitoring chip, you would need additional hardware to make the LEDs flash, where as the Microcontroller would be a single chip solution. In my opinion the Microcontroller would be the way to go, but you would need to learn how to program it.
FWIW: Its not a good idea to use a relay to switch between AC and invertor for your loads.
>And the other stuff is, and then is higher than +- 250V it must convert it back to usable 12V DC for the inverter
And then lower than 220V it must make it also useable 12V for my Inverter for an sort of alternative Energy source then the voltages are messed up
You would need a Buck converter with PFC. Although I think this maybe beyond your experence and if your not very careful it could be lethal. Below is a short article on how to step down AC into 12V DC using a PFC regulated Buck converter.
http://www.semisouth.com/application/AppsNote_Safe_Buck_Converter.pdf
However, I if was going to design it, I would probably leave out the 12V inverter and use a PFC coupled to a SMPS that produces synthized AC output at 220V. Using this method, there would be no distortion of the output AC waveform since no input transition is required (ie AC to 12VDC back to AC), and it would be more efficient since there is very little voltage difference between the source and the output. With the 12V inverter, the voltage needs to be dropped to 12V (losses) and then stepped back up to 220V (more losses). You're going to lose a lot of efficiency with this method. This design is a lot more complicated than going with the 12V inverter.
Normal State in between = Green LED
Lower than +- 220V = Yellow LED “R”
Lower than +- 10V = Flashing Yellow LED “R”
Probably the simplest way to do this is with a microcontroller that has a built in ADC. A small 8 or 14 pin microcontroller could be programmed to monitor the voltage using the ADC (using a voltage divider of course) and each LED would be connected to I/O pins on the Microcontroller. You would write code to monitor the ADC output and turn on or off output pins. This can be done in a software loop to make the LEDs flash. Alternatively you could use a set of voltage comparors like the LM311. You would need to use a reference voltage and configure a voltage divider so that it's output matches the reference voltage. I believe the LM311 datasheet contains example circuits for low or high voltage detection. There are also voltage monitor chips available, (I believe MAXIUM makes a bunch) but I believe the majority of these chips are surface mount and are geared towards battery management for portable devices. But using a voltage comparor or monitoring chip, you would need additional hardware to make the LEDs flash, where as the Microcontroller would be a single chip solution. In my opinion the Microcontroller would be the way to go, but you would need to learn how to program it.
FWIW: Its not a good idea to use a relay to switch between AC and invertor for your loads.
>And the other stuff is, and then is higher than +- 250V it must convert it back to usable 12V DC for the inverter
And then lower than 220V it must make it also useable 12V for my Inverter for an sort of alternative Energy source then the voltages are messed up
You would need a Buck converter with PFC. Although I think this maybe beyond your experence and if your not very careful it could be lethal. Below is a short article on how to step down AC into 12V DC using a PFC regulated Buck converter.
http://www.semisouth.com/application/AppsNote_Safe_Buck_Converter.pdf
However, I if was going to design it, I would probably leave out the 12V inverter and use a PFC coupled to a SMPS that produces synthized AC output at 220V. Using this method, there would be no distortion of the output AC waveform since no input transition is required (ie AC to 12VDC back to AC), and it would be more efficient since there is very little voltage difference between the source and the output. With the 12V inverter, the voltage needs to be dropped to 12V (losses) and then stepped back up to 220V (more losses). You're going to lose a lot of efficiency with this method. This design is a lot more complicated than going with the 12V inverter.
I have some circuit diagrams on how to a 555 timer IC for a Low Voltage Battery Disconnecter
To my understanding this Buck converter with PFC only give you 12V DC from an “variable ?” 170V DC source.
But will it be possible to convert a variable voltage source from like say example:
Between 40V AC and 200V AC >> to 220V AC because our 3 phase transformers get half switched of and only working on 1 or 2 phases and that give us a scrappy 110V AC and all our equipment buzz like the fridge and the lights go on some cloud 9 dim mode.
And once in the cape in a complex like +- 7 years ago, one of the big transformers had a nervous breakdown and gave 400 houses 380V AC and make roof fans spin like a air plane propeller and turn the light on super bright like mode and open and close all the CD players the complex, it have destroyed my dad’s Hifi Set and was unable to repair it at the repair shops only like a year ago the TV got fixed and cost a half fortune. Luckily nobody had pc’s running 600GB drives stored with all their music and videos that time
I’m currently using a relay to switch between inverter or mains and that only gives me a millisecond power dip but will hope to some day to fix that problem.
Just for interest sake will a SRC work better than a relay?
To my understanding this Buck converter with PFC only give you 12V DC from an “variable ?” 170V DC source.
But will it be possible to convert a variable voltage source from like say example:
Between 40V AC and 200V AC >> to 220V AC because our 3 phase transformers get half switched of and only working on 1 or 2 phases and that give us a scrappy 110V AC and all our equipment buzz like the fridge and the lights go on some cloud 9 dim mode.
And once in the cape in a complex like +- 7 years ago, one of the big transformers had a nervous breakdown and gave 400 houses 380V AC and make roof fans spin like a air plane propeller and turn the light on super bright like mode and open and close all the CD players the complex, it have destroyed my dad’s Hifi Set and was unable to repair it at the repair shops only like a year ago the TV got fixed and cost a half fortune. Luckily nobody had pc’s running 600GB drives stored with all their music and videos that time
I’m currently using a relay to switch between inverter or mains and that only gives me a millisecond power dip but will hope to some day to fix that problem.
Just for interest sake will a SRC work better than a relay?
Two things - for the "power good" function, there are commercial relays available. To roll your own, use a small transformer (say 230/12V 0.2A). Use 2 rectifiers - one with a large output cap to power your circuit (and make sure your cap has extra voltage rating to live through overvoltage condx) say 1000uF 35V, one smaller with discharging resistor to measure AC voltage. Look for a "window comparator" circuit powered from rect #1, input from rect#2, to activate a relay in the "good" range only, relay=off is automatically standby mode then.
For actually drawing power from undervoltage supplies, check whether you can use some SMPS with wide input range (100-250V is common). These don't come for higher power specs however, you may have to parallel several; charge a battery from these & run an inverter at the output. Inverters for 12V/230V (car) or 24V/230V (truck) use are relatively cheap up to ~300W, DIY requires better-than-average knowledge & test equipment.
For actually drawing power from undervoltage supplies, check whether you can use some SMPS with wide input range (100-250V is common). These don't come for higher power specs however, you may have to parallel several; charge a battery from these & run an inverter at the output. Inverters for 12V/230V (car) or 24V/230V (truck) use are relatively cheap up to ~300W, DIY requires better-than-average knowledge & test equipment.
jacquesl said:
The article refers to using a Buck converter to reduce rectified AC voltage into semi-regulated 12VDC. You would need to design a Buck converter that operates at ~310VDC (Rectified 220 AC). Alternatively, a 220 to 120 step down transformer could be used (assuming that the power load doesn't require a huge transformer that breaks your budget).
>12V DC from an “variable ?” 170V DC source.
The rectified DC voltage remains nearly constant. Thats what the purpose of the PFC. It boosts the voltage when the AC line voltage (following the sine wave) drops below 170V. PFC uses a Buck boost circuit to help keep the voltage stable at 170VDC. During a brown out the PFC would boost the voltage back up to 170VDC.
jacquesl said:
A more cost effective solution would be to use a "quality" surge suppressor that has built in overvoltage protection. When the voltage exceeds the recommended voltage it trips an internal breaker that isolates your electronics from the mains. You can purchase whole house systems so you don't need to install two dozen units to protect everything. Look for units that use crossbars instead of MOVs.
Relays cause spikes that could damage senstive electronics and the contacts can wear out pretty quickly. It would be better to avoid using relays in your design.
You might want to see if there is a home power inverter that might do what you need it to do. Companies like Trace make inverters for off-grid/unreliable-grid that can use Grid Power and battery. They probably also have electronics to deal with brown-outs and overvoltage conditions built into the unit. It would probably be much more practical and cost effective solution for you.
I am also concerned that your lack of experience make this project way too dangerous. If you really want to get serious with this project, it would be prudent to broaden your experience and knowledge by learning about SMPS, and experment with low voltages first! AC mains voltages are extremely powerful and danagerous. Even one very small mistake could kill you. Its not worth your life to save a few bucks, and you must first learn how to walk before you can run a marathon. To design a reliable regulated AC inverter is very difficult.
jacquesl said:
The ubiquitous TL431 makes a pretty good comparator with a voltage reference -- Texas Instruments illustrates how in the product folder. For the inbetween condition you need a window comparator.
- Status
- Not open for further replies.