5 Vdc wall wart and under rated 5 Vdc regulator
hmlittle59
Posts: 404
Hello All,
First, Thanks Chris S. for getting me back on line with the forum.
Although this PCB has gone from "Concept" board to.....Maybe near production quality, one must always make the test set up and components as important as though it was production.
MEANING:
I've modified some code (DS1302 Demo Code) Chris Savage and (JulianDate) for day of the week Tracy Allen. I've also written a lot of custom routines (Day Light Savings Time DLST) & (DS1302 AutoBoot),along with other routines. But if you don't have a good start (Power Supply (wall wart)) and 5 VDC regulator, you can be for ever chasing problems. I've modified, re-written, changed code over and over again because I did patch work on my power connection and got an under rated 5 V regulator.
The wall wart has about 4 different voltage settings, so that worked great. But it has a 4 prong connector on the end so it will not physically plug in. So I patched in another 2 connectors and it worked for a while. Also along with an under rated SMT 5 Vdc regulator, it has been one big "DOG CHASING HIS TAIL" problem. During final testing of the 5 slot BS40p code things started to fall apart(literally). The solder connection was breaking down causing the LCD Screen to flicker during certain test. This lead me to believe the code was bad. That started days of rewrite. After going through 4 wall warts that may have "COOKED" my under rated 5 V reg. , I rebuilt the original cable/connector to a better standard. The same problem was their, YES, more re-write of code. I isolated it back to the Voltage Regulator and switch to a thru hole 7805 reg. and then purchased a hand held blow dryer and nearly cooked the work bench and it would NOT fail. Lesson learned... I hope. So now the hunt is on for a VERY GOOD (SPEC.) SMT + 5vdc reg. ....."BUY CHEAP, BUY TWICE".
For all that want to start a project and go cheap and take short cus, it does not always pay off and can cost lots of wasted trouble shooting time.
my two cents...hope it can help some one new......or.......old.
First, Thanks Chris S. for getting me back on line with the forum.
Although this PCB has gone from "Concept" board to.....Maybe near production quality, one must always make the test set up and components as important as though it was production.
MEANING:
I've modified some code (DS1302 Demo Code) Chris Savage and (JulianDate) for day of the week Tracy Allen. I've also written a lot of custom routines (Day Light Savings Time DLST) & (DS1302 AutoBoot),along with other routines. But if you don't have a good start (Power Supply (wall wart)) and 5 VDC regulator, you can be for ever chasing problems. I've modified, re-written, changed code over and over again because I did patch work on my power connection and got an under rated 5 V regulator.
The wall wart has about 4 different voltage settings, so that worked great. But it has a 4 prong connector on the end so it will not physically plug in. So I patched in another 2 connectors and it worked for a while. Also along with an under rated SMT 5 Vdc regulator, it has been one big "DOG CHASING HIS TAIL" problem. During final testing of the 5 slot BS40p code things started to fall apart(literally). The solder connection was breaking down causing the LCD Screen to flicker during certain test. This lead me to believe the code was bad. That started days of rewrite. After going through 4 wall warts that may have "COOKED" my under rated 5 V reg. , I rebuilt the original cable/connector to a better standard. The same problem was their, YES, more re-write of code. I isolated it back to the Voltage Regulator and switch to a thru hole 7805 reg. and then purchased a hand held blow dryer and nearly cooked the work bench and it would NOT fail. Lesson learned... I hope. So now the hunt is on for a VERY GOOD (SPEC.) SMT + 5vdc reg. ....."BUY CHEAP, BUY TWICE".
For all that want to start a project and go cheap and take short cus, it does not always pay off and can cost lots of wasted trouble shooting time.
my two cents...hope it can help some one new......or.......old.
Comments
I'm all for making things on the cheap!
However, when designing and experimenting there is nothing better than some good bench top equipment,
1. A good quality digital meter. Fluke is the best but there are many lower cost ones.
2. A good lab bench variable power supply with a fine resolution current limit control. Make sure it has an analog output regulator.
3. A relatively good digital oscilloscope.
There are lots of other equipment for special requirements but the top 3, in my opinion, are required.
Good stuff is low cost in the long run.
Duane J
If you are going to do anything successful with electricity, both need adequate consideration. You don't have to buy a bench power supply, but you do have be sure you have ample power from the source to provide to the device at or below its voltage limit.
Regulated voltage is important to microcontrollers as the clocking is stable and the i/o is within expected limits.
Regulated voltage and regulated current have a lot of uses, but most of us are mainly interested in these in terms of battery charging.
And there is a point that 'too frugal' locks one out of really doing ambitious projects. It is like trying to rebuild a car engine with a pair of vise grips and a set of screw drivers. There are right tools, and then there are tools that just get you started.