# trying to make a 12v latch work off batteries in combination with wireless remote

#### iwishiwastesla

Joined Mar 5, 2016
3
Hello

I have just joined this forum after seeing how active the creative community is on here.

I hope that you can provide me with some advice this is my first electronics project and i am having a bit of trouble putting it all together.

None of these parts have been ordered as of yet as i am trying to figure out the most optimal combination of components to put together to make this work. So if the components i have posted on here are no good and you know something better please do advise.

What i would like to have is an electronic latch that is operated on battery power and controlled by a wireless one button remote to activate the latches release function.

here is a link to the latch i am looking at using:

http://www.alibaba.com/product-deta...60317325240.html?spm=a2700.7724838.0.0.h7s4v7

here is the remote and the receiver that i would like to use:

http://www.aliexpress.com/store/pro...Switch-DC6V-9V-12V-24V/320366_1455004549.html

The challenge is how to make it run off the least amount of batteries, preferably only one 9V battery.

#### Papabravo

Joined Feb 24, 2006
16,116
I don't understand the relation of the two components. I suspect you may need some other parts as well. What makes you think the latch will respond to the remote key? Are you really going to buy 100 pieces to get the price to the $3-$5 range. You know that MOQ stands for Minimum Order Quantity -- right? Where are you located?

Just noticed from the datasheet, that the minimum operating voltage is 12Volts. It is probably not practical for you to build a boost egulator to get +12V from a 9V battery. The current requirements is kind of high for battery operation.

You should read the datasheets more carefully. It is tedious and boring to do this but it saves you from asking other people if things will work.

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#### iwishiwastesla

Joined Mar 5, 2016
3
as far as i understand i just need the battery pack and the wires so essentially

it should look like this :

battery pack --(+/- wires)-- receiver --(+/- wires)-- latch

once i press the button on the remote the receiver sends a charge to the latch and releases it

http://www.aliexpress.com/store/pro...Switch-DC6V-9V-12V-24V/320366_1455004549.html

as for the price of the components it is irrelevant to me i just need to make one of these work.

the question is how do i most effectively power this and if these are not the correct components do you know what ones would do the trick?

#### AnalogKid

Joined Aug 1, 2013
9,249
This will not run off of one 9 V battery. The latch mechanism requires 12 V and can draw up to 2 A. Even if it were rated to operate down to 9 V, a single 9 V battery cannot supply 1-2 A while maintaining a 9 V output.

Separate from that - how many activations do you require a single battery or battery charge to support?

Finally, given the amount of stuff on ebay, why are you ok with buying 100 pieces of something when you need 2?

ak

#### iwishiwastesla

Joined Mar 5, 2016
3
the
This will not run off of one 9 V battery. The latch mechanism requires 12 V and can draw up to 2 A. Even if it were rated to operate down to 9 V, a single 9 V battery cannot supply 1-2 A while maintaining a 9 V output.

Separate from that - how many activations do you require a single battery or battery charge to support?

Finally, given the amount of stuff on ebay, why are you ok with buying 100 pieces of something when you need 2?

ak

The manufacturer does allow sample orders of this product so i can get only one i just need to pay the shipping from china to canada

i do not require many activation's maybe 5 in total would work great

while 1 battery would be optimal i don't mind using more i just need to know what the most effective way to do this would be without using a ridiculous amount of batteries.

#### Papabravo

Joined Feb 24, 2006
16,116
I can see this working from a deep cycle marine battery. You get +12V and they are rechargeable. A 9V battery just won't work period, done, full stop. But hey if you're an optimist and don't believe me then try it out and see for yourself. You don't even have to wait for the parts from China, just get a 5Ω 50 Watt resistor and connect it across a 9V battery and see how long it can maintain the 9V it is supposed to put out. Will it be long enough to open the latch? I don't know. How may times will it do it? I don't know that either, but you will, and you might just prove me wrong.

#### AnalogKid

Joined Aug 1, 2013
9,249
Can you handle rechargeable batteries like ni-cads or a sealed lead-acid (SLA), or do you want to use only primary (non-rechargeable) cells? Eight AA batteries in series should do what you want, and you can buy 8-battery holders pre-wired for this.

ak