Good morning all, I am no expert on electrical devices in any sense, however I am designing a laser line for a particular saw. I'm in search of a PCB that can transform 110vac to 5vdc that also has a battery on it. The idea is that the particular accessory outlet on the saw that I will be using to power the laser is only hot when the saw is running, obviously that's not good while trying to match up a scribed line with a laser line. My thought here was to have a battery that can power the laser while the saw is off and the 110vac can keep the battery charged while the saw is running. I'm looking for something off the shelf if possible. I'm still in prototype phase and after speaking with a few PCB manufacturers, it wouldn't be plausible to have something custom made at this point.

Any info would be greatly appreciated.
Thank you in advance!
Let me know if there's any more info I can provide.

 

Why not forget the battery and power the laser from a wall adapter?

 

Why not forget the battery and power the laser from a wall adapter?

That was my original setup but there's no good way for the power cord routing. I would prefer to keep everything on the saw.

 

If you get one of these USB --> 18650 battery charger modules and connect it across a 18650 battery.....





and one of these 18650 ‐-> USB boost converter modules




and connect it across thev18650 battery, you'll have power to the laser as long as the saw is powered up long enough to keep the battery charged.

 

If this is a table saw or some other sort of system , not a handsaw, then the solution would be to add an unswitched outlet to the power switch box. That will require a box, an outlet, and a bit of wire. Total cost less than $10 (USD). Then you will be able to use a 5 volt wall-wart and not be concerned with any battery or open circuit boards.

 

If this is a table saw or some other sort of system , not a handsaw, then the solution would be to add an unswitched outlet

That's not plausible for the end user.

 

I'm really just looking for what I originally posted about. Other suggestions/ideas have already been thought out and discarded.

 

Add a USB charger to what I described in post #4. This is precisely what you asked for, although you'll need to put it in a small box.

 

Add a USB charger to what I described in post #4. This is precisely what you asked for, although you'll need to put it in a small box.

Much appreciated. I am looking for something off the shelf. I understand if that's not possible. However this will be a product that I will resell and I do not have the experience or liability insurance to sell an untested non-UL listed electrical device that I've assembled myself. I'm not trying to burn down anyone's shop haha.

 

This is not a specific recommendation, but an example of the genre:

https://www.ebay.com/itm/204386706205?hash=item2f9665a31d:g:tGoAAOSwZBVkpGrv&amdata=enc:AQAIAAAAwKAC4Nf9RoO5oIOvaltkvBYQ4OVwZ0SfIUkJAArS/zrJl3540iNqpGnDcbZyT9B/bhfgM9CnamxkSbSYBSuRu9iD1Z6svwuA33VQcNm651ajFjlOc1OchU91eaPMiVJasMK7dg/XdWQzW2tKh3z0ccXvUkJTNcoBqdgfRFh68CMGkqml8H2vRUC3ruqFKQ5IUzcYHkBRC2WDCI3r6dp7zrBdZqtHXpTud7PazcdwmFBygmMuZUuf24/HnQdZWjvQkw==|tkp:BlBMUJSuhL2nYw

This is a USB power pack. It is a lithium battery with both a charging circuit (5 V input) and an output boost converter regulated to 5 V. Most come with a charging cable that might not be long enough for your situation, but cables are cheap. You also need a 5 V USB wall wart.

Search ebay and Amazon for USB battery pack, USB power pack, USB power bank, travel backup power, cell phone battery backup, etc.

Most of these kinds of devices have the old, large, standard USB-A output connector. However, there are 4 (!) possible USB connectors for the charging input. Make sure your cable, or your wall wart with an attached cable, has the correct USB connector to match the device's input.

Here is one that uses AA batteries - no charger:

https://www.ebay.com/itm/313624203334?hash=item4905759046:g:g4AAAOSwEQ1guZrl&amdata=enc:AQAIAAAAwBMWUSjVOVHAomH+YmE3vwaCEMg1YYhDyWAUKDet0564/fZSE+QLiP5YBH+dKuuvrkv5h/ZUAXyR0ulw5OBI1Qr70xu4d5LTh3NgV6x7jZpmnH00Gd2Z/vAjeALWJqXOZsBt1dODqqfvyzIXaV934bynK+g2hrEr8WTgjJk0G8Bvy3WWmiEk/gSPj2MR3/ZADOHmNQa1PEI3TKJpFYzk5XbwSnNQxss4/8x7zqyc034Ixw6X8Y1jp1+1/v8IcOxEyQ==|tkp:Bk9SR9iTt72nYw

Once you've got the battery device you want, You will need an output cable that plugs into the battery pack and goes to the laser. You don't say what the current requirement for the laser is, or anything about its power input connection, but you have to figure that out no matter what the power source is. If it is a barrel connector, there are "universal" power banks that come with an assortment of barrel connectors.

All off-the-shelf components. Buy the wall wart from a reliable company so you know the safety certifications are not faked.

ak

 

Will a USB power bank charge and provide power at the same time? I believe most of them do not.

 

Welcome to AAC.

Here is an example of a candidate module. Search on AliExpress (or elsewhere) for “5V UPS module” for more options. To provide the 5V input, use a standard phone type charger. You can expose the Type-C jack on the module or put your own on the box wired to the pads on the module, and and either supply or require the user to supply (much better) a charger.

This one uses two 18650 cells which will provide a very long run time.
You can also get single cell modules, or versions for LiPo cells.

​

 

Welcome to AAC.

Here is an example of a candidate module. Search on AliExpress (or elsewhere) for “5V UPS module” for more options. To provide the 5V input, use a standard phone type charger. You can expose the Type-C jack on the module or put your own on the box wired to the pads on the module, and and either supply or require the user to supply (much better) a charger.

View attachment 313495
This one uses two 18650 cells which will provide a very long run time.
You can also get single cell modules, or versions for LiPo cells.

​

Does the battery need to match the 5v input? My laser module is 5vdc but all the batteries I'm seeing are 3.7v

 

Does the battery need to match the 5v input?

No. The electronics have two functions:

a) Voltage and current regulation for charging the battery.

b) Boost conversion to raise the battery voltage to 5.0 V for the output.

ak

 

No. The electronics have two functions:

a) Voltage and current regulation for charging the battery.

b) Boost conversion to raise the battery voltage to 5.0 V for the output.

ak

Would there be any issue with putting in a switch between the board the laser module?

 

Would there be any issue with putting in a switch between the board the laser module?

No.