For valentines day I decided to make my valentine a picture frame that slowly pulses on and off (like a heart beat) when it is picked up. You can use the same tequnices to make a pulsing light effect on other projects like a computer case mod. Swap out the heart shaped frame for the shape of your choice and the red LEDs for your favorite color.
The frame is made with two small pieces of plexiglass. and the finished frame is no bigger than 5.5" but could be made to any size. LEDs inside light the bottom larger layer of plexiglass. The light will catch on anything that gets in its way between the LEDs and the edge of the plexi. I etched a message in the border which then becomes easily visible when the frame is lit.
The circuit I hacked together from some other more complicated designs is enterally analog and requires no voltage regulation. This means that the circuit should last a long time on a single 9v battery because the 555 timer chip is running directly off of the 9v battery and can continue to use the 9v as a power source as it falls well below the the 9v value. It should continue to work all the way down to ~4v as the 555 only needs 3.3v minimum and the led's only need ~1.4v . A micro switch underneeth turns off the pulsing effect when not in use and the frame is only turned on when picked lifted off of the surface it is resting on. This means it further saves power by only operating when someone is holding it and looking at it. Other modifications could easily be added to make it light sensitive or moation activated as well.
All of the electronic parts necessary should be available at your local electronics store as well and only basic soldering skills are needed to assemble it.
The frame is made with two small pieces of plexiglass. and the finished frame is no bigger than 5.5" but could be made to any size. LEDs inside light the bottom larger layer of plexiglass. The light will catch on anything that gets in its way between the LEDs and the edge of the plexi. I etched a message in the border which then becomes easily visible when the frame is lit.
The circuit I hacked together from some other more complicated designs is enterally analog and requires no voltage regulation. This means that the circuit should last a long time on a single 9v battery because the 555 timer chip is running directly off of the 9v battery and can continue to use the 9v as a power source as it falls well below the the 9v value. It should continue to work all the way down to ~4v as the 555 only needs 3.3v minimum and the led's only need ~1.4v . A micro switch underneeth turns off the pulsing effect when not in use and the frame is only turned on when picked lifted off of the surface it is resting on. This means it further saves power by only operating when someone is holding it and looking at it. Other modifications could easily be added to make it light sensitive or moation activated as well.
All of the electronic parts necessary should be available at your local electronics store as well and only basic soldering skills are needed to assemble it.
MVI_2444.AVI(640x480) 19 MB
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You will need only a minimum amount of tools and materials to create this project. I used 1/8" plexiglass I believe that I had in my garage. Beyond that you will need a picture, photoshop is good to use because you can easily scale and play with the layers. You will also need a project box, a 555 timer, a 100uF capacitor, a 100 ohm resistor, a 500 ohm resistor, a 9v battery, and a few small other parts like a switch and proto board to put everything on.
The key to the circuit is using a 555 timer to create a slowly fading in and fading out pulsing effect wile not going completely dark. I have tried many different pulsing circuits until I found one I liked. I then modified it until it had the fewest parts possiable. You could make it without the pcb if you wanted and just solder the parts together. (pcb posted soon)
The key to the circuit is using a 555 timer to create a slowly fading in and fading out pulsing effect wile not going completely dark. I have tried many different pulsing circuits until I found one I liked. I then modified it until it had the fewest parts possiable. You could make it without the pcb if you wanted and just solder the parts together. (pcb posted soon)
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Hope it helps someone..
sean
I'm using an LM555 timer and a 2n2222a transistor
what could possibly be wrong?
I've reworked the circuit, stared at the schematic for... a half hour and i have yet to reach a conclusion on anything i could have done wrong, so i'm thinking my parts might be.
Can please specify what kind of transistor you used? Correct me if I'm wrong, but I think I need a PNP 9V transistor with a max current that suits the LEDs.
are you sure the circuit above is right? Threshold (6) and Trigger (2) are both Inputs and there is nothing else connected to them...
I tryed this with a 5v Input and a BC337 instead of the 2N2222.
The LED won't light up until I pull the 100uF but *suprise* then there is no PWM..
Any hints?
I have a NE555N, a LM555CN and a 7555CN (Phillips).
If I test them with the schema I created (still with a BC337) all fade in and the 7555CN also fades out yeah! I don't know whats the cause of this behaviour... weird analog circuits ;) I'm always open to more theory about it.
About the schema:
Afaik if two Pins are going to GND it doesn't matter which hits GND first. On the breadboard Pin 1 is connected to GND (blue wire hiding line 11 on the breadboard) and without this connection there is no fading (tested ;).
Pin 4 & 8 use both *the same* VCC. If you use Eagle and try to create a board out of this schema the two VCC will be the same signal. So no need to connect them in the schema. To be true, it would be nice to know how to *make different voltage sources* with eagle. I've attached the Eagle schema if someone wants it.
Download -> open with eagle -> FAIL
Download -> save to disk -> rename to .sch -> open with eagle -> Works
Tested on WinPX, Firefox 3.something, Eagle 5.4.
and im running windows7 X64
maybe i have designed it wrong... i will try again but do not know why my polaritys were in reverse.