I made this good looking beating heart (.. Accidently invented near the valentines day. ;)).The device has 20 LED`S that blink at a hardware specified rate. Unlike the conventional approach of using micro-controllers i though using a simple 555 Timer would be great ..adding to it ..it would simplify the design and make it less cuber-some for those who either have no prior knowledge or dont want to waste time gathering the same.
Here`s the thing you might get after going thru the rest of the instructable.
Step 1: Getting the Supplies
Things that are required:
1 x NE555 Timer
2 x 10k Resistances
1 x 100uF Electrolytic Capacitor (25V)
1 x 10uF Electrolytic Capacitor (25V)
1 x 9V Battery / 3 x CR2032 Li-ion
1 x Through hole board
1 x 9V Battery connector
1 x IC Base (8 pin)
1 x Push Switch ( to avoid ur heart beats in front of everyone:D)
20 x "identical" Red LED ( Identical is the catch in here.. as if they are sourced differently u might end up having uneven brightness..which will be disappointing)
Wires as required..( it goes to like " Salt to taste")\
And lastly "Spare Time"
Other Things that might be available at hobbyists are:
soldering Iron, Solder, Flux, Tweezers, wire cutters, Helping Hands ( Clamp tool)and hot glue gun.
Step 2: The Concept
Now that u have stuff..lets find out what actually is this-
NE555 is the most generic of all timers . Its supply range is 5V To 15V ( We are comfortable with 9V..).Its output current from datasheet is about 200mA which is enough to drive those 20 LED`s of mine..
Using an externally coupled circuit it can be used to decide the time a particular pin goes high or low( Thats called Timimg).
The rate of charging and discharging are determined by the RC Circuit.
To calculate your own custom timing which is subject to availability of components-http://www.ohmslawcalculator.com/555_astable.php
The timer runs in the Astable mode in our project ( to know more on this -https://www.instructables.com/id/Know-Your-IC-555-Timers/)
Now the circuit-
The LED`s are connected in parallel (so that one apple doesnt spoil the basket ) which makes connections easier.
I would suggest you to please pre-prototype the circuit on a breadboard and then make it towards the next steps( it adds to the motivation part)
Step 3: Building It-1
After you have pre-prototyped it ..you need to do the following things..
1. In order to make the heart look a heart( specially for people with bad sketching as mine) please draw a heart on the non etched side of the PCB using a permanent marker and then proceed in laying the LED`s..
2. Since LED`S are round they are ought to follow the line as they can be placed with the two legs either vertically or horizontally.
3. Solder the legs and mark the positive ones.
4. Then clip the legs.( Thats the exciting part)
5. When you are done..solder the IC Base.
Step 4: Building It-2
Now that you have soldered it will..Its time for the nasty thing..
CONNECT ALL RANDOMLY ORIENTED +ve Pins together.
and all -ve together.
You might have to make some common grounds somewhere and other modifications.
At the end of the exercise do test the +ve and -ve terminals with a continuity tester and say "crap" if the beep sounds.C
You will end up with something like this.
After all`s well..put hot glue gun to further reinforce the wiring..( That`s optional)
Then solder the components as in the circuit given earlier.
BEWARE- Do not connect the +ve of the battery supply to the LED.. Becoz thats what we have 555 for!
Step 5: Final Looks
Now..you have done it..here you have ur beating heart.
The completed Pics are-
You can keep this in your pocket ( if u wear a shirt) and switch it on..at the right time..
Also if you need to add more Leds you can use FETs and other things.
Hope you get your heart beating..
Thanks for being through this..
Please give your comments and suggestions.
Thats my First Instructable!
Hope i was able-to-instruct well..
Participated in the
Valentine's Day Challenge