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Help me with my LED Voltage Level Indicator.

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hi,
The LM3914 has 10 LED's which you want to display 0 to 30Vdc on, OK.
So thats 30v/10, ,, an LED will light for every 3V increase on the Vsig input.
This means you will have resistor divider across the 1.25V to 30V output of your power supply.
The divider will drop the 30V down to 10V for the Vsig input

I would use a 20K and a 10K divider.

So you connect the LM3914 as shown in this image.
Pins 6 and 7 are linked together, do not connect pin 6 to any other voltage

Do you follow OK.?
 

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hi,
Ref our Chat, look at this marked up drawing.
 

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hi,
Ref our Chat, look at this marked up drawing.

Thank you so much ericgibbs. I'm done now with the circuit design. Here it is.

My problem now will be the pcb layout. I'm required to use only the bottom copper of pcb.
 

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Thank you so much ericgibbs. I'm done now with the circuit design. Here it is.

My problem now will be the pcb layout. I'm required to use only the bottom copper of pcb.

hi,
That looks OK, the C3 value should be higher, say 100uF or 220uF

Single sided PCB's are quite common,,, copper on the back side and components on the front side, use solid tinned copper wire for the 'track' on the component side.
Wire size about 24 SWG,
 
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