I've breadboarded that circuit when other members have tried, and failed, to have an LED turn off completely.it works pretty well..
its a 9 volt supply and the LEDs are 3 to 3.4 voltI've breadboarded that circuit when other members have tried, and failed, to have an LED turn off completely.
I can't do any calculations for your circuit because you didn't provide supply voltage or LED on voltage. The base current for the transistor that's on has to flow through the LED that's supposed to be off. Any efficient LED will turn on dimly with small currents.
That circuit shouldn't work. The LED current will be over 200mA. That means the base current of the transistor needs to be 20mA (unless you're using a Darlington - no part number for the transistor).its a 9 volt supply and the LEDs are 3 to 3.4 volt
TIP 120 Darlingtons. The question is not if this works or issues with that circuit. It a way to alter it to give a different effect. I have no issues out of the current circuit.That circuit shouldn't work. The LED current will be over 200mA. That means the base current of the transistor needs to be 20mA (unless you're using a Darlington - no part number for the transistor).
With a 9V supply, you'll also be reverse biasing the base-emitter junctions enough to kill transistor beta. Signal diodes anti-parallel to the base-emitter junctions will prevent that.
That gives better conditions. Base current will still be almost 1mA. Must be some very inefficient LEDs if they don't light dimly at 1mA.TIP 120 Darlingtons. The question is not if this works or issues with that circuit. It a way to alter it to give a different effect. I have no issues out of the current circuit.
if they are dimly lighting, i cant really tell with a 3watt led. The blue drowns out any white that may be dimly lit and the same vise versa so it does not really matter for either light would be on at a time.That gives better conditions. Base current will still be almost 1mA. Must be some very inefficient LEDs if they don't light dimly at 1mA.
i know but with amazon i can get my money back by tomorrow if they are fake. of course the kit that i got does not have the cd4017I hope the assortment of ICs from Amazon (China) are not fake ones. Look in Google for the company that makes the assortment: SWPEET. The ad in Amazon is written in Chinglish.
Hey I appreciate the time and help. I will have to order that chip.OK, this is NOT a complete diagram. It's intent is to show how I would go about getting the double flash on one side then on the other. The NAND gate chip is a quad dual NAND gate chip. Using two chips for the LED's and the other two chips can be used to create the clock pulse. A bit more complex than you're asking for - but it's how I would have gone about solving the problem. Not shown is the power source and current limiting resistor for the LED's. Also not shown is the two extra NAND's for the clock pulse.
View attachment 227374
you would just change the capacitors. the bigger the cap the longer the time is.Sounds good in theory, but I would suspect some timing issues, without some feedback method to tell the control osc. when to switch.
Control osc. = circuit 1.
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by Jake Hertz
by Jake Hertz
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