Sorry for the crude drawing. But this is a way to do it with the least amount of parts. When the door is closed, nothing is energized so the red led is on saying the door is closed. When the door is open, the reed switch is closed thus energizing the relay and turning on the green led, saying the door is open. Doing it this way would use the least amount of power because nothing is energized when the door is closed
The way i hooked mine up at home uses even less parts. I used an old iphone charger as the power supply, a limit switch on the garage door and a flashing LED. The limit switch is wired up so when the door is down the limit switch is open and the LED does not flash. Once the door opens, the limit closes and the LED flashes. Pretty sure that is the easiest way with the least amount of parts.
Oh I agree with you. Was just saying that the original person had it with the 2 , so I did it also with 2. I'd rather have it that there is only an LED lit when the door is open.
Ok, so add in an extra LED and it is still less parts than you suggested :-) Personally I would find it annoying to have an LED on constantly telling me the door is closed.. That is why I just have an annoying flashing light which alerts me that the door is open as at the end of the day you are only really concerned if the door is left open.
Interesting design, and it does use very, very few parts. Personally I would just use a CMOS Inverter that would consume less power vrs a Relay. The use of a mechanical device vrs a Digital device (IMO) tends to introduce a less reliable functional Ckt... but that's just me. Yet many of today's PCB type of Relays are very reliable.
P.S. I am also trying to figure out how to attach a sketch drawings... but I see you got it to work. Very good!!!
Very interesting using of NOR gate! But I think you just needed one or two transistors for this circuit (BC547 for example). This would simplify the scheme
Yes Sir... the two Transistor Ckt was my first draft and it worked well on the breadboard, although in my case I used the 2N3904 NPN ( seems to be more common and very inexpensive in North America). Anyway, I wanted something a little more elegant and creative in the CMOS digital world... thus I went with a spare NOR gate IC that I had on hand. The use of a 7404 or 4049 would probably make for the simplest Ckt with the fewest parts (two LEDs, two Resistors, and one IC), but I did not have any of these ICs on hand. As referenced before... there are many, many ways to make this simple logic Ckt.
Overall... my driving purpose here was a Garage Door Indicator for the Bedroom... with the material I had on hand. And as a Hobbyist, like me... have some fun and see how creative I could be with the parts I had on hand!! At the same time, an elegant and creative design (IMO) does not always mean a design with the fewest parts, although that can be a rewarding goal for a Ckt design at times.
If you have the time, I would very much appreciate your design ideas for a proven Ckt with the fewest parts, be it with Transistors or ICs. I wounder if this could be done with just Resistors and Caps??? Now that would be an interesting design.
Thanks for you comment! Your design inspired me for a new instructable about this theme and now I work on it. I think I'll publish it on this or next week.
IMO it's all about placing an Indicator "of some type" in the Bedroom to indicate that the Garage Door is open or closed!!!! We can all talk about this or that design... but the real prize is the peace of mind, at feeling reasonably assured that the "Door is Closed" when we look up at the indicator!!!
Just as an FYI but green means safe and red means unsafe... So normally when applied to equipment you would have green as closed meaning the door is closed and all is safe. Then red would mean the door is open and it is unsafe and someone could steal your stuff.
After reviewing the circuit, it seems you actually used the two input NOR gates as INVERTERS and not NOR gates. So you could have used a 7404 or even a 5404 series Hex Inverters to accomplish the design and therefore could use 5 volts as the logic voltages. Those simple hex inverters are very cheap and available. Nice idea either way and good project.
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22 Comments
bluesea8 7 years ago
Sorry for the crude drawing. But this is a way to do it with the least amount of parts. When the door is closed, nothing is energized so the red led is on saying the door is closed. When the door is open, the reed switch is closed thus energizing the relay and turning on the green led, saying the door is open. Doing it this way would use the least amount of power because nothing is energized when the door is closed
gadgetgogo 7 years ago
The way i hooked mine up at home uses even less parts. I used an old iphone charger as the power supply, a limit switch on the garage door and a flashing LED. The limit switch is wired up so when the door is down the limit switch is open and the LED does not flash. Once the door opens, the limit closes and the LED flashes. Pretty sure that is the easiest way with the least amount of parts.
bluesea8 7 years ago
bluesea8 7 years ago
gadgetgogo 7 years ago
Ok, so add in an extra LED and it is still less parts than you suggested :-) Personally I would find it annoying to have an LED on constantly telling me the door is closed.. That is why I just have an annoying flashing light which alerts me that the door is open as at the end of the day you are only really concerned if the door is left open.
bluesea8 7 years ago
maxx99 7 years ago
Interesting design, and it does use very, very few parts. Personally I would just use a CMOS Inverter that would consume less power vrs a Relay. The use of a mechanical device vrs a Digital device (IMO) tends to introduce a less reliable functional Ckt... but that's just me. Yet many of today's PCB type of Relays are very reliable.
P.S. I am also trying to figure out how to attach a sketch drawings... but I see you got it to work. Very good!!!
bluesea8 7 years ago
Whole drawing doesn't show up unless you click on it, sorry.
geovas333 7 years ago
Very interesting using of NOR gate! But I think you just needed one or two transistors for this circuit (BC547 for example). This would simplify the scheme
maxx99 7 years ago
Yes Sir... the two Transistor Ckt was my first draft and it worked well on the breadboard, although in my case I used the 2N3904 NPN ( seems to be more common and very inexpensive in North America). Anyway, I wanted something a little more elegant and creative in the CMOS digital world... thus I went with a spare NOR gate IC that I had on hand. The use of a 7404 or 4049 would probably make for the simplest Ckt with the fewest parts (two LEDs, two Resistors, and one IC), but I did not have any of these ICs on hand. As referenced before... there are many, many ways to make this simple logic Ckt.
Overall... my driving purpose here was a Garage Door Indicator for the Bedroom... with the material I had on hand. And as a Hobbyist, like me... have some fun and see how creative I could be with the parts I had on hand!! At the same time, an elegant and creative design (IMO) does not always mean a design with the fewest parts, although that can be a rewarding goal for a Ckt design at times.
If you have the time, I would very much appreciate your design ideas for a proven Ckt with the fewest parts, be it with Transistors or ICs. I wounder if this could be done with just Resistors and Caps??? Now that would be an interesting design.
geovas333 7 years ago
maxx99 7 years ago
IMO it's all about placing an Indicator "of some type" in the Bedroom to indicate that the Garage Door is open or closed!!!! We can all talk about this or that design... but the real prize is the peace of mind, at feeling reasonably assured that the "Door is Closed" when we look up at the indicator!!!
geovas333 7 years ago
P.S. My new instructable done! If your interested in it - see my profile.
maxx99 7 years ago
Very nice... makes for a great "look see" at the simplicity that can be achieved with a little reflection on the given project. Thanks for sharing.
geovas333 7 years ago
Thank you too, for idea and for review :)
geovas333 7 years ago
Of course I'm understand you! Feel of protection is our all!
I'm just a PhD so I try to find scientific thing in all around :)
gadgetgogo 7 years ago
Just as an FYI but green means safe and red means unsafe... So normally when applied to equipment you would have green as closed meaning the door is closed and all is safe. Then red would mean the door is open and it is unsafe and someone could steal your stuff.
JimM38 7 years ago
How could you transmit the state via wireless?
maxx99 7 years ago
I'll leave that one to someone else...
gm280 7 years ago
After reviewing the circuit, it seems you actually used the two input NOR gates as INVERTERS and not NOR gates. So you could have used a 7404 or even a 5404 series Hex Inverters to accomplish the design and therefore could use 5 volts as the logic voltages. Those simple hex inverters are very cheap and available. Nice idea either way and good project.