I make with some simple circuits. I have a lot of questions on this hobby. I want to build a 10 led voltage indicating circuit for 5 to 15 volts, d.c. Bought several lm3915. Will the lm3915 work or do I need the lm3914? I would like the results to be 1.0 volt per led. Thank you for any help.
I make with some simple circuits. I have a lot of questions on this hobby. I want to build a 10 led voltage indicating circuit for 5 to 15 volts, d.c. Bought several lm3915. Will the lm3915 work or do I need the lm3914? I would like the results to be 1.0 volt per led. Thank you for any help.
If chuck has a V+ between 16.5V and 20V, he could set up the internal reference to 5V and apply that to RLO, amplify the 5V reference to 15V with a gain-of-3 op amp, and apply that to RHI. Then the input signal would not require level shifting.
hi all!
Can you tell me pls in detail, how can i increase low threshold of input signal?
I built VU meter with 0...1v range and now i want build meter with 1...2v range and then use they as single 20 leds meter with 0...2 v range.
Can you add short scheme if possible.
hi all!
Can you tell me pls in detail, how can i increase low threshold of input signal?
I built VU meter with 0...1v range and now i want build meter with 1...2v range and then use they as single 20 leds meter with 0...2 v range.
Can you add short scheme if possible.
yes, i read datasheet, but not quite understand how specifically regulated
threshold of 2nd IC.
Is the R6 regulated low threshold ? **broken link removed**
The ratio of the resistors determine the reference voltage of each LM3915 IC.
The reference voltage at pin 6 determines how much input voltage lights each LED.
They are 30dB apart from each other so that the lowest one displays up to 0.3V and the highest one displays up to 10V.
so, is this sheme correct? **broken link removed**
R1 regulated high threshol of IC1, grounded pin4 set low threshold of IC1 to 0v.
R2 regulated high threshol of IC2, voltage from Rhi (pin6) of IC1 shift low threshold of IC2 to 1v.
That's the circuit for the LM3914 display, which is linear. LM3915 is logarithmic, so your best approach would be to use fig. 5 or fig. 6 in the **broken link removed**. Read the accompanying text. The LM3915 needs 10V full scale audio to accurately display 60dB dynamic range. Amplify your 2V input signal by 5.
that sheme work not bad, but i think i will use single IC with shifted zero, for better visibility.
In any case cascaded lm3915 will give something like this: **broken link removed**
or i am wrong?
that sheme work not bad, but i think i will use single IC with shifted zero, for better visibility.
In any case cascaded lm3915 will give something like this: