This was kind of a rush thing I did today because I have a few projects awaiting various IC's which I can't publish yet but I haven't posted anything this week so I thought I would lash up a LED Ring Oscillator - I'm sure you've seen these things on the net in various guises, mine has increasing value resistors which basically makes the oscillator more predictable in the way it rotates and which LED starts first which was quite important for this as it's going to be part of a LED/LDR circuit
you'll notice that the schematic I've done isn't in my usual notebook format but instead I used a program from the CD off the front of a magazine called circuit wizard - it's okay for testing little circuits like this so I thought I would just upload the schematic I drew in that
anyway as usual the stripboard has been built up and it works - the rate is voltage controlled so the less voltage you feed into it the slowed the LEDs will light up - my favorite voltage is about 3.3v which is cool for uController projects that already have that voltage available - I've tested mine upto 16 volts but I couldn't go any further due to the capacitors I was using.
Great stuff! I built this thing on a solderless breadboard and it works great. Any recommendations on how to vary the components to get different blink rates? Or is there a good place in this circuit for a potentiometer?
ReplyDeleteif you lower the input voltage you get slower blink rates
ReplyDeleteI just built this and all I get is 3 solid LED's. Now I did use 56k's for the 47k's and 1.5 for the 1.2. Is that my problem? I just hooked a 9v battery to it. Thanks
ReplyDeleteit could be aye. however make sure there are no whiskers of solder down the stripboard
ReplyDeletecheck transistor pinouts (I have often made that mistake)
also try lowering the input voltage - I hope you get it working cause it is a nice effect
http://www.paulinthelab.com/2012/08/using-stripboard-key-to-my-diagrams.html
Yes, fatigue soldering allowed me to install the transistors backwards. Swung them around and it works like a champ. Thanks. Another question, if I may. What is controlling the amount of dim each LED exhibits? In other words, is there a way to make the LED have more contrast between on and off? I plan on using this circuit for a theater prop generic electronic device. Just an object with flashing lights. I want to make sure the effect is enough to be seen from the audience. I will use slightly larger LED's for one. Am I making any sense? Thanks again.
ReplyDeletebasically just less voltage - around 4 volts works best for me so you could take your 9volt supply and use a resistor divider to get it down to about 4.5v like this www.electronicproducts.com/images2/facd_IRC_fig1_oct2009.gif use 2 10k resistors
ReplyDeleteThanks. I'll try it
ReplyDeleteBigger the caps slower the transitions or
ReplyDeleteBigger the resistors slower the transitions and vice verca...
Have a look at mine
http://www.usbelectronickits.com/rgb-mood-lamp---pr003.html
not bad, I may do a stripboard for yours if I run out of ideas. I did think of using a regulator to get a more constant result but in the end I decided "bugger it" cause it was just a quick project to make a bigger one look nicer.
Deletelooking at your site we have a lot of similar types of projects, yours of course more professional looking but still. I'll link you into my links page.
WHAT THE BLUE LINE FROM E2 TO M2 STAND FOR???
ReplyDeleteit's a jumper wire - there is a diagram here to guide you with the layouts on this site http://www.paulinthelab.com/p/tips-and-troubleshooting.html
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