gres
Full Member level 4
Small smart calculator
Project is based on old Unitra Brd 12U calculator. Design is elegant and small. All is built at one - side boards without any jumpers
Calculator built up of two boards - main and keyboard. At main board we have all electronics. I wanted to make effective double decker construcion so all elements must be with right high.
Display
I solder goldpins to holes in display and placed into obliquely board. That display placed make lecture easier, and good place for battery. To avoid removing battery, at bottom side of board i glued neodymia magnet.
I had some problems with keyboard. It's difficult to solder pins straight. After bought pins at shop they had black strip- i pulled pins so the list was close to ends of it. That makes easier soldering and remove strip. Worse thing was with 3 free pins at the bottom of the board. You need to be careful to avoid braking pins!! After solder all pins I flood them with glue. Keyboards goldpins doesn't go into board as display, but into DIL20 board. Pins that are close to display has 6mm long, those further 4,5
At buttons I put foil with symbols. I printed it at house printer in mirror mode - it's becouse symbols are from bottom side.
Holes i made by drill 3mm hole and melt by worm metal cone,
At bottom side of calculator I placed styrofoam stripes to avoid scratching table.
More information at https://www.elektroda.pl/rtvforum/topic1518735.html
Project is based on old Unitra Brd 12U calculator. Design is elegant and small. All is built at one - side boards without any jumpers
Calculator built up of two boards - main and keyboard. At main board we have all electronics. I wanted to make effective double decker construcion so all elements must be with right high.
Display
I solder goldpins to holes in display and placed into obliquely board. That display placed make lecture easier, and good place for battery. To avoid removing battery, at bottom side of board i glued neodymia magnet.
I had some problems with keyboard. It's difficult to solder pins straight. After bought pins at shop they had black strip- i pulled pins so the list was close to ends of it. That makes easier soldering and remove strip. Worse thing was with 3 free pins at the bottom of the board. You need to be careful to avoid braking pins!! After solder all pins I flood them with glue. Keyboards goldpins doesn't go into board as display, but into DIL20 board. Pins that are close to display has 6mm long, those further 4,5
At buttons I put foil with symbols. I printed it at house printer in mirror mode - it's becouse symbols are from bottom side.
Holes i made by drill 3mm hole and melt by worm metal cone,
At bottom side of calculator I placed styrofoam stripes to avoid scratching table.
More information at https://www.elektroda.pl/rtvforum/topic1518735.html