Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
so the pot configuration for measuring pin 7 would be the same if i were to use it on the alarm flasher cct right? Hmm.. say i want to have two of these bar displays (with alarm flasher).. but they're not cascaded, just separate from each other. is it possible to control it with only one pot...
@ericgibbs : sorry, i thought u were talking about the alarm flasher circuit! :) yes, i tried it with a 4K7, and it actually takes more turns for the pot to light each LED one after another.. so i'm guessing the voltage level for each LED is improved with that..
@audioguru : that's a new...
hehe.. i don't know which 3K8 u're talking bout. but i did try playing around with various resistor values at the -V end of the cap.. it has improvements for bigger resistors, but the effect is not that significant anyway, but still does what it says on the tin. i guess i need to stop playing...
So I tried.. adding the 1k resistor improves it just a little bit. maybe i just need to get over it and learn to say 'good enough'. hehehe..
may i know the reason why you suggest 1k though? do you still use the Vrefout formula in the datasheet to determine the max input signal?
Certainly, it's the battery. why didnt i think of that? lol. I hooked the circuit with a dc psu at 9V and it works like a charm.
Another question..! -_-
I also build another circuit, which is "Bar Display With Alarm Flasher" (attached schematic).. it's in the datasheet but i use it with...
Hi!
it works fine now.. after replacing the 2.2uF cap with a 100uF (thankfully I have 2 stocks of those!). so nothing's damage..yet! my room must be really 'noisy'..
another concern though, the LEDs light up accordingly when I turn the pot wiper. but, i don't often get the whole 10 LEDs...
Thank you EricGibbs for correcting me.. i believe the wiring is now ok seeing that the LEDs light up when i hook it with the 9V battery.
CarlosFandango, yes when i finally wired it correctly according to the schematic EricGibbs posted, it's already very bright! :)
But there's another...
Hello, I'm new in this forum. I've read this thread and I've learnt a lot from it. However, I tried constructing the exact circuit as in the LM3914 datasheet with a pot.
Attached is my schematic..
My problem is, when I turn the wiper of the variable resistor, the LEDs won't light up...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
