Circuit for a 2 digit LED display

[Gregory]

Student.
I have a 24V 5amp power supply and would like to install a 2 digit Display to read the variable Voltage I require .
Could any one supply me with a circuit digram to enable me to make and install this Display.
Thanking you Greg.

 

[crust]

You can either buy a prebuilt module which has the inputs, logic, and LCD built in or ..... You can condition the signal so that it has an acceptable input range for an ADC. Then you can use a microcontroller to convert the digital value to an appropriate display (such as 7segment LED, etc). There are also some ADCs that directly drive 7 segment displays, but I have not used one at that voltage range. There are lots of suggestions on how to do this as it is frequently asked on this board.

 

[Sebi]

It called ICL7107. 3and half digit with all 7segment outputs.(no multiplexed) Basically +-199mV input, can easy to modify with a simple divider and shunt.

 

[elec_lover]

Attention: For some reason you can not use the power supply itself to power the digital voltage panel, you will possible blow up the measuring module.

 

[Sebi]

Yes, good point. When the GND of measured voltage and panelmeter supply must be common, need an additional negative supply. For 7107 + and - 5V according datasheet (or appnote - i don't know) if You need, i search it...

 

[Exo]

**broken link removed**

 

[k7elp60]

2 digit LED display

You could use a CA3161E/CA3162E pair, It will give you three digits and uses a common power supply ground, and works of a single power supply voltage.

 

[hornerm]

You could use a CA3161E/CA3162E pair, It will give you three digits and uses a common power supply ground, and works of a single power supply voltage.

These chips are no longer standard. The factory stop making it.

Use ICL7107. These use less supply to built.[/quote]

 

[JimB]

Consider using a digital multimeter.
There are DMMs available very cheaply from Maplin (UK). I recently bought one for £3 (if I remember correctly).
One of these could probably be re-packaged into the power supply for less cost than a scratch built voltmeter.

JimB

 

[kinjalgp]

Use ICL7107 based Digtal Panel Meters (DPM) with appropriate voltage divider network. DPMs are readily availabe at low cost.