This listing is for an LM317 based power supply DIY electronics kit with a 0-20v digital voltage display that is used to show you the voltage that is at the output terminal block. This kit was designed after so many people were interested in the kit that we used to offer based on the instructable below. We also sell these fully assembled for a few dollars more, so check out our store!
The input voltage acts to power the 0-20v display,which consumes very little current. The seven segment displays are multiplexed, so it requires less than 20mA to operate. There is an on-board 9v regulator chip that protects the supply of the display, so that you can use an input voltage of up to 20VDC (20 volts DC). The LM317 will work with input voltages between 3VDC-9VDC, but the display will only work when there is more than 8v at the input. If you have an input voltage of 18v, then the output voltage can be varied between 1.25v and 18v. If you have an input voltage of 3v, then the output voltage can be varied between 1.25v and 3v. These are just some examples.
It is suggested that you use a wall transformer and an on/off switch with this kit. My suggestion would be to find a wall transformer that can output between 8v-20v@1A, or higher to place at the input terminal block. The LM317 can output up to 1.5A if well heat sinked, but it will start to get hot. Try to keep your load current under 1A if possible. The video above shows you how to put this kit together from scratch. When you purchase this kit, you will receive the custom printed circuit board, and all of the parts required for assembly. No hard copy of the instructions are included. The instructable listed above talks about how the device works, and the video shows you how to operate the device when it is complete, as well as how to put it together. WATCH THE VIDEO! IT WILL HELP YOU LEARN WHAT THIS KIT IS ALL ABOUT!
Please note that we also sell these fully assembled for a few dollars more.
Requirements:
1) For the display to work properly, the user should have between 8-20VDC at the input terminal block.
2) If you don't have a 8-20VDC supply, you can still use this kit with lower input voltage, but the display will not operate. At least not correctly. If you have less than 8v at the input, a varied voltage between 1.25v and your input voltage can be found at the output terminal block. It is preferred that you have 9v or higher at the input terminal block for the display to work, but it will still operate when only 8v is at the input.
3) Attention to detail.
4) Some soldering/DIY kit assembly experience would be helpful!
If you have any questions, please do not hesistate to ask!
This product was added to our catalog on Saturday 07 January, 2012.
