| special-k |
While I'm not completely clueless when it comes to basic circuits, I really only possess a cursory knowledge of this stuff.
I know there's quite a few electrical gurus here. I seek your help.
I am looking to make a simple (simple for those who know how these things work, of course) circuit to create some accent lighting at my house. I have a very high shelf in my living room (cathedral ceilings) and I came up with the idea of taking some empty wine bottles and doing some decorative lighting with them. What I'm going for here is a series of white LEDs (1 - 2 per bottle?) and an infrared receiver / switch so that I can turn them on/off with my universal remote (again -- the shelf is well out of normal reach). Assuming the IR receiver won't drain a battery too fast, I'll probably want to use a 9V battery (or maybe a couple lithium batteries) to power it. If all else fails and batteries become a huge hassle, I can install an electrical outlet up there and use a DC power brick if I have to.
(afterthought: however, if I installed an electrical outlet the need for this is almost moot since I could just use one of those X10 remote on/off power adapters... but I digress)
A slightly enhanced version of this might use some of the ICs that are available (which I don't know how to use.... heheh) to maybe have multiple states selectable by the remote. Perhaps on, blink in series, random, etc. But that's totally unnecessary and would only be for added effect. One thought that I had was instead of only having on/off states, I might like to add a third state which uses a photo sensor for an "auto on/off" state which is based on ambient light in the room.
I found a couple things that might be a good starting point:
http://www.instructables.com/id/Uni...-Remote-Switch/
http://simerec.com/chips.html
(I'm thinking the SIS-1 or SIS-2 ?)
If anyone is willing to help me out with this I would appreciate it!
Thanks! |
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| Tyler_Canada |
The IR receiver shouldn't use a measurable amount of current when nothing is being received. That said, fluorescent lights trigger IR receivers a lot, but because the receivers don't respond unless the "code" is correct, most people don't know that.
Lithium batteries may not be as useful as NiMh, as they drain faster when not in use (they're most useful for high current applications). I doubt your LEDs would be considered high current (the reason for picking them).
The second page you listed has exactly what you need. There is a circuit diagram that is what you want, just change the mains power to battery, and the relay to the appropriate voltage. |
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| special-k |
quote:
Originally posted by Tyler_Canada
The IR receiver shouldn't use a measurable amount of current when nothing is being received. That said, fluorescent lights trigger IR receivers a lot, but because the receivers don't respond unless the "code" is correct, most people don't know that.
Shouldn't be an issue, there are no fluorescent lights in proximity to that room.
quote:
Lithium batteries may not be as useful as NiMh, as they drain faster when not in use (they're most useful for high current applications). I doubt your LEDs would be considered high current (the reason for picking them).
Good point, I will keep that in mind. I was just looking for something that would last as long as possible so I only have to get on a ladder to change the batteries as infrequently as I can get away with. :)
quote:
The second page you listed has exactly what you need. There is a circuit diagram that is what you want, just change the mains power to battery, and the relay to the appropriate voltage.
Right, that's what I figured. That's kind of where I fall off though, I'm not sure how to calculate the proper relays, resistors, etc. Also, I don't need any of the AC stuff (for the lamp) since I won't be powering anything AC. And if I wanted to augment that design with the photo cell I wouldn't know where to begin with that.
Thanks. |
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| Tyler_Canada |
| Ok, I can help with that. I'll need a little while to work it out, should have something later today. |
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| Tyler_Canada |
So you'll need 4 AA's to run the receiver circuit (assuming you're using rechargeables, alkalines would initially be too high a voltage). Unfortunately, the IR receiver does draw power while idle. It's about 10mA, which means you should get at least 400 hours (possibly up to 800 hours) of use with 4 batteries (take the mAh rating of the battery, divide by 10). If that's not sufficient, I could come up with other options (lantern battery?).
Radio Shack parts:
275-1549 (Mini SPDT 3-Amp Momentary Pushbutton Switch) S1
275-409 (2-Pack 3-Amp SPDT Sub-Mini Slide Switch) In place of jumpers ABC
272-1069 (0.1µF 50V 10% PC-Mount Capacitor) 0.1µF
276-309 or 276-330 (Red LED)
275-232 (Compact 5VDC/1A SPST Reed Relay)
270-391 (4 “AA” Battery Holder)
276-003 (Modular IC Breadboard Socket)
You don't need J1 (just connect pin 7 to ground).
More to come. |
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| special-k |
quote:
Originally posted by Tyler_Canada
If that's not sufficient, I could come up with other options (lantern battery?).
Thanks for that so far.
A lantern battery might be a good option. That would save me lots of trips up the ladder and money, too. Since it's up so high, it shouldn't be too hard to hide it.
The circuit wouldn't change at all, would it?
BTW -- what was J1 that you said was not necessary? |
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| Tyler_Canada |
We would have to add a voltage regulator to use a lantern battery (the chip calls for 5V max, but the battery would be 6V), but it's not too complicated.
J1 is a jumper that allows you to change whether the circuit defaults to on or off. It's irrelevant since one button press will switch it. Without the jumper, it defaults to off anyway, which should be what you want. |
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| Tyler_Canada |
Updated parts list:
Radio Shack parts:
275-1549 (Mini SPDT 3-Amp Momentary Pushbutton Switch) S1
275-409 (2-Pack 3-Amp SPDT Sub-Mini Slide Switch) In place of jumpers ABC
272-1069 (0.1µF 50V 10% PC-Mount Capacitor) 0.1µF
276-309 or 276-330 (Red LED)
275-232 (Compact 5VDC/1A SPST Reed Relay)
276-003 (Modular IC Breadboard Socket)
276-2058 (2N4401 NPN Switching Transistor)
271-1313 (220 ohm 1/4W 5% Carbon Film Resistor pk/5) Resistors connected to transistor and LED
276-563 (1N4742A 1-Watt Zener Diode)
276-1770 (+5V Fixed-Voltage Regulator 7805)
You may notice that the Zener diode is rated to 12V, and not the available 5V model. The reason is a bit complicated, but it is that value that indicates when current will travel "backwards" through the diode, which is what we don't want in this case. |
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| Tyler_Canada |
The transistor is like a mini relay, it provides more current to turn on the relay, as the chip can only produce a minimal current on the output.
The diode is needed because the actual relay contains an induction coil, and when turned off they generate reverse current. The diode dissipates that current and prevents it from killing other components.
The resistor on the transistor is there to keep the current below the max output the chip is capable of. Voltage = Current X Resistance. We know the voltage is 5V, the max current is 0.025A, so the resistance should be at least 200ohms. Since the closest higher value you can get is 220ohms, that is used.
The resistor on the LED is there to protect the LED. A red LED drops 1.6V, so we still have 3.4V to drop. A typical current for a red LED is 20mA, so a 170ohm or higher resistor is needed. Since you'll already have 220ohm resistors, they'll do fine, the LED just won't be quite as bright.
By choosing 1/4 watt resistors, they can dissipate more heat, and will last a lot longer than using a smaller value like an 1/8 watt or smaller. I suppose you could also go with 100ohm resistors, and put two in series for each, giving 200ohms, but space may become an issue. The part number for the 100ohm resistors is 271-1311.
Using the SIS-2 will allow you to have the light sensitive setting you would like, without much more complication. |
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| special-k |
Wow... OK. I'm following most of what you wrote but when we get into diodes and backwards current I start to lose ya. :)
As I currently (no pun intended) understand it, this circuit will handle the on/off switching, but no provisions have been made for the series of white LEDs that will actually be the lighting component of this whole thing. The one red LED is the "ready to program" indicator, according to the drawing I'm looking at, correct? When we start to add in the white LEDs for the actual lighting, how do they fit into calculations for adding resistors and such?
Since I won't be powering anything AC, I'm assuming we just take the stuff in the gray shaded box (relay, DC coil) out? Or does the relay somehow stay but independent of the coil?
Right above the gray shaded box, there is a component that looks like an LED but is shaded in black. Is that the zener diode? I don't recognize that symbol.
Sorry for being so clueless here... I think one of my next "personal enrichment" exercises will be taking some electronics / electrical classes. I really would like to have a better understanding of this stuff. I should have majored in electrical engineering or computer engineering instead of computer science. :) |
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| Tyler_Canada |
That's correct, no provisions have been made for the white LEDs, although that part will be quite easy. You'll need a resistor or two depending on how many LEDs you have, and that should be it. It won't affect the resistors we've already listed.
The relay in the grey box will become a 5V relay, which will power the LEDs. Instead of using mains power, you'll use battery power, but you'll still need the relay.
Yes, the component that looks like an LED is the zener diode. That symbol is universal for diode, and you'll notice the LED has a little lightening bolt next to it to indicate that it's a light emitting diode. |
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| Tyler_Canada |
For the white LEDs, you need the LEDs and one resistor each.
276-320 (5mm White LED)
You'll need 120ohm resistors for optimal brightness, but you can't get those from Radio Shack (at least they don't list them online). |
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| special-k |
quote:
Originally posted by Tyler_Canada
For the white LEDs, you need the LEDs and one resistor each.
276-320 (5mm White LED)
You'll need 120ohm resistors for optimal brightness, but you can't get those from Radio Shack (at least they don't list them online).
Ok, that's helpful, thanks.
Let's say I had 8 white LEDs -- 2 per bottle and 4 bottles. Would they all be wired in series with each other, and one resister for all of them, or one resister for each? What happens if I wire them in parallel? If each one drops 3.6V and I have 8 of them, in series that would mean I'd need 28.8V? Since we only have a 6V (5V?) power source I'm guessing they'd have to be wired in a combination of parallel sets in series?
I'm guessing 2 LEDs per bottle simply because I don't know how much 1 LED is going to light up each bottle, since the glass is tinted dark. Maybe I only need 1 per bottle.
The relay breaks the + voltage line, correct? So, the LEDs get wired on the + side from the output of the relay, and then the - side gets brought back around to where the ground / negative battery terminal is?
Thanks again for all your help.
Oh, and there's a Sandy's Electronics here where I can most likely get anything that I can't get at Radio Shack. |
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| Tyler_Canada |
Correct that the relay breaks the + line and the - goes back to the battery.
You have to wire all the LEDs in parallel, in order to use with a 6V power source. Because there is some variance in the voltage drop each has, you have to put a resistor on each one, or else the LED with the least drop will take all the current and burn out.
Something about white and blue LEDs is that they are a LOT brighter than standard red, green or yellow. You should probably start with one per bottle. |
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| special-k |
quote:
Originally posted by Tyler_Canada
Correct that the relay breaks the + line and the - goes back to the battery.
You have to wire all the LEDs in parallel, in order to use with a 6V power source. Because there is some variance in the voltage drop each has, you have to put a resistor on each one, or else the LED with the least drop will take all the current and burn out.
Something about white and blue LEDs is that they are a LOT brighter than standard red, green or yellow. You should probably start with one per bottle.
Thanks for everything Tyler.
Something that has me a little confused, though... is it 6V going to the LEDs or 5V? I thought we had the voltage regulator to limit the entire circuit to 5V, which would mean that since the white LEDs are rated at 3.6V, that leaves 1.4V and 20mA so I would need... a 70 ohm resistor on each LED? Or... is that wrong?
Maybe a drawing would help. I'm pretty visual when it comes to understanding this stuff. :2: |
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| Tyler_Canada |
The voltage regulator is only for the control circuit. The LEDs are going to get 6V, minus the drop over the resistor(s). The less current we put through the voltage regulator, the better. It has to convert the excess power to heat.
I wish I had a circuit diagram software, but I'll use MS Paint and whip something up. |
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| Tyler_Canada |
| Sorry, it's going to be tomorrow night or Monday morning, I have to leave town this morning for a birthday. |
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| Tyler_Canada |
| Ok, sorry it took me so long, it's been a crazy week. |
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| special-k |
quote:
Originally posted by Tyler_Canada
Ok, sorry it took me so long, it's been a crazy week.
Thanks... that's very helpful.
Based on my limited understanding of this... I assume the 5V voltage regulator goes inline between the 6V source and where it connects to pins 1 and 4 of the SIS-1 chip, right?
And the switch works by completing/cutting the path to ground for the LEDs?
Seems to make sense. I'll use this plus your previous parts list (very helpful!!) and hopefully I will have some time to sit down and tinker with this soon.
One additional question... I've always found it somewhat cumbersome to try and solder wires "in-line" with each other -- such as, a wire lead connecting to an LED lead. Do you have a technique that you use? I've always had a hard time getting two straight wires to stay in contact with each other while applying heat and solder. Twisting them together really isn't feasible either.
Thanks again for your help. This is exactly what I needed. |
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| Tyler_Canada |
Oops, yeah, I forgot the 5V regulator. You're correct about where it goes.
S2 allows you to test with the LED, then switch to actual operation. It's used for programming the button you want to use on the remote as well. Then when you're all set up, you switch it and power goes to the relay instead of the LED.
One of the parts I included was a solderless board. There are holes you push wires into, and the holes are connected in certain patterns. In this case, all the holes down the sides that are marked + or - are connected, and in the middle the holes are connected in rows.
Another option is a solder board. It has holes you put the wires in, and copper pads around each holes that you can solder the wires to. Then you connect the copper pads with either solder or a "pen".
As far as soldering wires to wires, it's easier to use twisted core rather than solid core. The most durable connection is made when you create a hook on the end of each wire, hook them together, then solder that. Don't forget the heatshrink! :) There is an item called "helping hands" (I think) that I have that's very useful. It's 2 alligator clips on movable arms that can hold the wires for you so you don't burn your fingers. |
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| SIM |
Too bad you don't have AC up there... Take a look at this:
Link |
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| special-k |
quote:
Originally posted by SIM
Too bad you don't have AC up there... Take a look at this:
Link
That is pretty cool... but not exactly what I need in this case. I'm going to be putting LEDs inside of wine bottles to create a nice glow from the bottles up on a very high display shelf.
There are similar things out there like remote-controllable switching AC outlets. That would have solved most of this right fast, I could have just wired up a very simple circuit for the LEDs and then just switched the power on/off using the AC outlet. Trouble is -- all of the remote AC outlets I could find used RF not IR, which means I need to have yet another remote on the table. In the case of what we're doing here, I can program a button off my universal remote (IR) to control this switch.
If there are readily-available IR AC switching outlets, that might be an option too. At this point though, Tyler's design will meet my needs and the parts to put it together are cheaper than what those remote switch outlets cost.
I may still install an AC outlet up there (that's easy) just to eliminate the need to climb up a ladder and swap out batteries. I'll just use a 6V DC converter and all is happy. :) |
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| special-k |
quote:
Originally posted by Tyler_Canada
One of the parts I included was a solderless board. There are holes you push wires into, and the holes are connected in certain patterns. In this case, all the holes down the sides that are marked + or - are connected, and in the middle the holes are connected in rows.
Yeah... the stuff in the main circuit will be easy enough on the board. My issue was more with the wire leads connecting to the LEDs, which you mentioned below.
quote:
Another option is a solder board. It has holes you put the wires in, and copper pads around each holes that you can solder the wires to. Then you connect the copper pads with either solder or a "pen".
Yeah I've worked with those before. They're not too bad, but a little cumbersome without 3 extra hands. :) What is this "pen"?
quote:
As far as soldering wires to wires, it's easier to use twisted core rather than solid core. The most durable connection is made when you create a hook on the end of each wire, hook them together, then solder that. Don't forget the heatshrink! :) There is an item called "helping hands" (I think) that I have that's very useful. It's 2 alligator clips on movable arms that can hold the wires for you so you don't burn your fingers.
I've tried that before, actually... the problem was usually with the leads that come off the LEDs. They're typically (at least the times I've worked with them) thicker and harder to bend without damaging them. Maybe I just need to be more patient with the needle-nose pliers. :)
I've heard of the "helping hands" before and I always end up at the same conclusion -- "well I don't do this stuff very often so I wouldn't use it much." Then, next thing I know, I'm wishing I had one again. LOL
At the risk of being the helpless fool who won't go away -- if we were to enhance this with the SIS-2 chip instead of the SIS-1 and a photocell to create a third state (on/off/auto), what would that entail?
Thanks! |
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| Tyler_Canada |
The pen has a silver based conductive ink, used for creating "traces" (connections) on circuit boards. The Radio Shack part is 64-4339.
I'll take a look at using a SIS-2 and adding an auto state. The chip itself has the same pins, the SIS-1 just doesn't use the extra output pin. We would have to add a photo sensor and that may be all we need. |
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| Tyler_Canada |
| So I was just about to upload an updated diagram with a light sensitive option, when I realized I had set it up to be a manual switch to toggle light sensitive mode, and that won't do. So I have to give it a bit more thought. |
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| special-k |
quote:
Originally posted by Tyler_Canada
So I was just about to upload an updated diagram with a light sensitive option, when I realized I had set it up to be a manual switch to toggle light sensitive mode, and that won't do. So I have to give it a bit more thought.
:2:
No worries, thanks!
Have a great Thanksgiving! |
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| Tyler_Canada |
Crazy week. Fiance's birthday, and we're going to New York city Friday.
So is an off state required? I can figure out how to make an on/auto setup, but I'm still working on an off state. The SIS-2 alternates the outputs. Maybe with a SIS-3, but I haven't looked at that one in detail. I know it's got more pins than the 1 and 2. |
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