# power jack and ac adapter

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#### MrDEB

##### Well-Known Member
researching for a smd power jack (
http://www.mouser.com/ds/2/670/pj-002ah-smt-516100.pdf

http://www.mouser.com/ds/2/670/pj-002bh-smt-516009.pdf
as well as an ac wall adapter
http://www.mouser.com/ds/2/410/media-1067545.pdf

http://www.mouser.com/ds/2/410/media-1068293.pdf

getting lost on getting the right jack to mate with the ac wall adapter.
Any one have success locating better choices?
calling CUI incx tomorrow to verify correct match etc. They have a mating guide but it only comes up with a plug that the user has to wire up. I want a self contained ac wall adapter with correct barrel connector on the end. Only looking at 50-75ma draw.

#### jpanhalt

##### Well-Known Member
You need to match the center pin and the barrel.

Your PS's have a center pin of 2.1-mm and a barrel of 5.5-mm diameters for both. Your 2nd link (BJ-002BH) has a pin diameter of 2.5 mm. That will not fit into a 2.1-mm hole without a whole lot of effort.

Your first link has a pin of 2.0 mm. That will fit into a 2.1-mm hole nicely. The outer dimension is less critical, as the contact is spring loaded. BTW, 0.1 mm is slightly less than 0.004", or a loose slip fit.

Given the two options you present for a wall wart, go with the first PCB connector. As for the wall wart itself, you need to decide between a bridge rectifier circuit and a full-wave circuit. Such comparisons are aplenty on the Internet.

John

#### JonSea

##### Well-Known Member
The first two supplies you linked are not regulated. If you draw the specified current, the nominal output voltage will be as listed. If you draw less than the rated current, the output voltage will be higher than the nominal rating.

You didn't say what voltage you desire....but if you can use 5 volts, why not use a USB connector? Doing so eliminates worries about jack size and correct polarity.

#### KeepItSimpleStupid

##### Well-Known Member
The 5 V ones are 5 V +-5% with 100 mV of ripple. 5 V 5% is typical. TTL operates usually to 5.5 V max.

#### JonSea

##### Well-Known Member
USB power supplies - available everywhere. How could they be anything except 5 volts?

The supply you just linked is a regulated switching power supply. Look at the input voltage range. If it can handle 90 - 240 volts input, it must be a switch mode supply. Look at the output voltage. regulated to +/- 5%.

If ypu look at cell phone chargers, virtually all of them are 5 volt supplies. Much of what I build is powered by a 2-buck cell phone charger purchased at the local thrift store. Chop off the connector, verify the voltage and polarity (red may mean plus to you, but not everybody sees it that way) and connect to the terminal block. Done.

Adding a USB connector is a nice option. You don't need to worry about polarity or the connector - it's all standard. Use a standard cable, a USB brick, multi-port changer or even a battery.

Full size USB-B jacks are great if you have the space. If not, MICRO-B is the best choice. I use a socket that fits in a cutout on the board; the cutout forces it to the correct position.

#### JonSea

##### Well-Known Member
This picture shows a micro-B connector and the board cutout where it fits. Soldering the pins is a little easier because the cutcut forces the connector into alignment.

#### MrDEB

##### Well-Known Member
Well $2.40 is better than$10 for sure. Will rethink my criteria. Just need to look for a jack and cord etc.
Thanks

#### MrDEB

##### Well-Known Member
curious?? a "cell phone charger" will keep the current flowing or shut down after charging? If it is continuous power then yes for a power supply but??
In post #7 where is the website?? looked at ebay and banggood??

#### Nigel Goodwin

##### Super Moderator
curious?? a "cell phone charger" will keep the current flowing or shut down after charging? If it is continuous power then yes for a power supply but??
Modern cellphone chargers aren't 'chargers' at all, they are simply 5V USB power supplies.

#### JonSea

##### Well-Known Member
Nigel is right. Most cell phones and many other products use 5 volt DC power supplies. Any charging intelligence is built into the device; the power supply is a constant voltage source.

These power supplies may have a USB-A connector in a brick or they may have a cable attached with a plug for the phone. This photo shows the power supply for a skin-care product. North American 2 prone inlet to a USB A connector. The input may range from 100 volts to 240 volts, and the output will be 5 volts at up to 550mA current draw.

#### JonSea

##### Well-Known Member
There are a couple things to be aware of. USB type C chargers and other high rate charging methods do supply more than 5 volts. Not to worry - changing voltages requires a communication sequence; if whatever the charger iis connected to doesn't commuicate, the supply voltage is 5 volts.

The other gotcha to using a random wallwart - some wallwarts provide constant current for LED lighting. These supplies specify output current over a voltage range.

#### JonSea

##### Well-Known Member
AC-DC Power Supplies - Using Wall Warts will explain some of the mysteries of AC-DC supplies. With the exceptions above, this is still excellent knowledge.

A trip to the local thrift store or pc-recycler will provide many high quality supplies.

#### MrDEB

##### Well-Known Member
The link Jonsea posted was the link I was looking for couple weeks ago but ??I recall Jon posted similar? on the DIY site.
I was/am considering installing a LDO 7805 on the board just for safety and using 7.5 wall wart but the cell phone charger looks like a better option.

#### JonSea

##### Well-Known Member
If you use a circular power connector, you need to worry about:

● Finding a power supply with a mating plug
● Finding a power supply of the correct polarity
● Finding a power supply of the correct voltage

Adding a voltage regulator to the board buys you a little protection from using a power supply with too high a voltage, but it means the power supply must be an oddball voltage or you risk overheating if too high s voltage is used.

You can add reverse polarity protection to get around the second issue, at the cost of additional components.

Or you use a USB connector. It need not even be built on the board - just use a USB pigtail. Polarity and voltage are defined, as is the connector. All of the above issues eliminated. If your device becomes separated from it's power supply, there's no question about power.

#### JonSea

##### Well-Known Member
My personal choice is MICRO-B, which I did not elaborate on. There are 2 reasons for this, despite easier-to-use packages in the mini size:

1. The mini size is crap and will become intermitent after not-many mating cycles

2. The mini-B jacks have been removed from the USB standard and are becoming difficult to source.

#### KeepItSimpleStupid

##### Well-Known Member
My \$0.02 worth:

I hate both USB and the circular connectors. There is a circular twist-lock. I had a device that needed a little bit of 12 V, I believe and they used a Phoenix contact connector.

You should be able to get 100 mA from a USB power supply. They are cheap and abundant until the new standard comes along.

A USB "power supply" rated at 2.1 A: Who knows if it follows the USB standard.

There is the OTG or "On the Go" standard which is the reason for 5 pins and only 4 on the normal USB. Some info is here: https://en.wikipedia.org/wiki/USB_On-The-Go

I think, you'll be fine, because the normal 5 V, 100 mA is the default amount of power available from a USB port. I would HOPE that an adapter to micro USB would use the OTG protocal. BUT, I THINK, that a lot of devices are using the micro USB just for power.

If I were worried, I'd consider a Linear Technology part that checks that power is acceptable.

EDIT: See Protection controllers: http://cds.linear.com/docs/en/product-selector-card/Surgestoppers_Rev_B.pdf

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