I’ve had a couple of viewfinder CRT modules for a while, & haven’t done much with them, so I decided to make a very small B&W monitor.
![CRT](http://www.experimental-engineering.co.uk/wp-content/uploads/2015/09/IMG_20150908_170946-300x225.jpg)
I ordered a small transparent ABS box when I made a large order with Farnell, that turned out to be just about the perfect size for the project! The CRT & PCB barely fit into the space. The face of the CRT itself is about 17mm across.
![Module Installed](http://www.experimental-engineering.co.uk/wp-content/uploads/2015/09/IMG_20150908_183718-300x225.jpg)
Here’s the main PCB & tube fully installed into the case. Barely enough room for a regulator left over!
Power is provided by a simple LM7809 IC to take a standard 12v input.
![Module Rear](http://www.experimental-engineering.co.uk/wp-content/uploads/2015/09/IMG_20150908_183735-300x225.jpg)
Rear of the case, showing the fit of the control board.
![Connections](http://www.experimental-engineering.co.uk/wp-content/uploads/2015/09/IMG_20150913_221649-e1442179199612-225x300.jpg)
Here’s the back of the monitor, with the DC input jack & a 3.5mm 4-pole jack for audio & video. This allows simple connection to many devices, including the one I’ll use the most – the Raspberry Pi.
![Completed](http://www.experimental-engineering.co.uk/wp-content/uploads/2015/09/IMG_20150913_221701-300x225.jpg)
Completed monitor. Audio is handled by a very small 20mm speaker, currently mounted just below the CRT face.
Current draw from a 13.8v supply is 117mA.