Hello Everyone!
I am doing a rebuild on my amplifier, and I would now like to add on two 5 inch LED bar meters to it. I am not too skilled in the digital side of things but all input is HIGHLY appreciated, more over to simple analouge. The amps is a very simple power amps with no VI protection. I may throw a speaker protector on it later.
I just need a circuit to drive these 50 red LED's!
The amp is 22 inches wide so two 5 inch meters leave just around 3 equal 5 inch spaces in the face, not including a power LED.
Thanks many in advance, GamerAndds!
Part 2 of my amp- https://www.youtube.com/watch?v=9KgotLiD3So
I am doing a rebuild on my amplifier, and I would now like to add on two 5 inch LED bar meters to it. I am not too skilled in the digital side of things but all input is HIGHLY appreciated, more over to simple analouge. The amps is a very simple power amps with no VI protection. I may throw a speaker protector on it later.
I just need a circuit to drive these 50 red LED's!
The amp is 22 inches wide so two 5 inch meters leave just around 3 equal 5 inch spaces in the face, not including a power LED.
Thanks many in advance, GamerAndds!
Part 2 of my amp- https://www.youtube.com/watch?v=9KgotLiD3So
Those use the LM3914/15/16 series ic, most of those ic's cannot do over 30 LEDs... Unless someone has a way to use 5 ic's with the 39xx series... The voltage swing of the output is +/- 60 volts... I would at least like to be able to tune it for +/- 70 volts... A simple resistor veidge will do this but... Help! I need to run 50 led, 5 bar meter segments- total of 5 inches!
I would also like the option to switch it from dot to bar, but I want it in dot mode if I cant get it to be switchable.
LM3914 series can be expanded from 20-100 steps according to the datasheet app. notes.
The voltage to be measured can be scaled by resistive dividers to any range you like - even transformer isolated if necessary. LM3914 MDC ... - Datasheet Search Engine Download
If you want every imaginable wizbang feature possible in a bargraph display, then you may have to think about developing your own multiplexed Microprocessor design and software. Then it's way out of the scope of an Audio power amplifier forum and into the everything else forum here or another group devoted to Microprocessors entirely.
The voltage to be measured can be scaled by resistive dividers to any range you like - even transformer isolated if necessary. LM3914 MDC ... - Datasheet Search Engine Download
If you want every imaginable wizbang feature possible in a bargraph display, then you may have to think about developing your own multiplexed Microprocessor design and software. Then it's way out of the scope of an Audio power amplifier forum and into the everything else forum here or another group devoted to Microprocessors entirely.
I'm surprised no one has a DIY kit to do the PL Series 2 type LED display. That's probably where the OP is going with this. I'm sure the original driver ICs are NLA - back in my college days I built one using 5 3914's and a 555 timer to do the full scale indicator. It does work and it's not that hard. Looked d*mn convincing in the dark - once I got the hold times correct on the peak detector and the flashing set of 4 on the end. I ended up re-purposing the 3914's to drive banks of colored PAR38 floods, as I needed those more at the time.
Thank you Ian, that does not seem to be the case with the 15/16 though? Can use 5 together, is it possible?
Thank you to my fellow canadian aswell, Micky Moose! I will get a closer look at it. The digital scares me but I will have to look into it!
Thanks aswell to Ripcord!
Thank you WG_SKI!! Those PL ones are wicked- my dad tells me all the time about them but their UAA170's chips are "NLA" as you said above- with great sadness! I was thinking about using some diodes with the LM39XX series to get a "back trace" and a cap to slow it down... but still thats 50 diodes and resistors per side!
You are pefectly correct, the phase linear 400, 700 and 500 is what im going for!
Now how to do it for 50 all driven.... in the circuit only 36 is driven and the last 4 just come on- which isnt bad but... I want 50 All Driven!! Muhaha 😀
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The biggest problem with getting 50 of them going is the signal getting noisy giving false readings. The low end of the scale is VERY low, and proper star grounding must be used for the signal and for the references for the dividers. The data sheet shows you what to do. Run things off a relatively high voltage, set the reference dividers to let full scale be say, 14 volts, and use op amps to amplify the signal ahead of the low range 3914's. The full data sheet (from the original paper bound data book) outlines the theory of operation. Read it, understand it, and work with one or two on a breadboard until you understand it fully. Then embark on the 50-element meter project.
I wish I still had time to play with this stuff. It was fun.
I wish I still had time to play with this stuff. It was fun.
I have a circuit to put up tomorrow, or late tonight. If you could just go thought it it would be awesome! You will see what I mean about the trail and ur opinion of that. Thanks for your input wg_ski!
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