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electronic door lock

AL13N

New Member
Thread starter #1
Hello,

There is an electronic door lock, of which i have no data, and i'm trying to figure out how to use it.

So, Installer gave me some documentation, but it seems to be wrong, i think another one is installed, so i can't trust the documentation:

The Documentation said: 12VDC -- 0.2A if it is in parallel ; 24VDC -- 0.1A if it is in series (it seems to imply 2 coils?) (it also said diode is included)

I have a 12VDC 50W powersupply, so i tested it:

When i connect the electronic door lock to the power supply, the powersupply goes into standby on/off

-----------

So what happened is i had supplied an ethernet cable, and asked him to connect it to the wires. The ethernet cable is cat 5e and is about 8m long.

But I don't know which wires are connected to what.

I tried some things and measured some stuff...

* the green - green/white pair seems to be directly connected, i measure 1.7Ohm of resistance
* the brown - brown/white pair seems to be having a resistance of 1.8kOhm
* no other wire (or combination) seems to be connected to anything

At first, i thought there must have been an error and 2 wires had been accidentally connected; but after some reading up, i can see that most locks have 4 wires of which 2 are a control to see if the door is closed or open. so, maybe the green - green/white pair is actually that one?

So, aftering measuring resistance of 1.8kOhm, if I would connect these wires to 12VDC i should get ~ 7mA (which is not 200mA; but well...) ==> which would imply 84mW (even if it would be 200mA it would still be 2.4W. granted, the powersupply is already used for something else too; but still all should be ok-ish.


How could i do more tests to find out how to wire this and use it?
 

AnalogKid

Well-Known Member
#2
PHOTOS? Image of the documentation or a link? Vendor site? anything?

Note - if the diodes are internal, then the lock is polarity-dependent. Connecting it to the ps backwards places the diodes directly the across the output for a short.

ak
 

AL13N

New Member
Thread starter #3
This is what i got, but as i said before, i'm not sure this is useful, since watts don't seem to match up...

i have no photo's, because the wiring is all hidden, i basically have a lock i can see on the outside (no branding visible) and i have an UTP cable on the other end...

I did try to measure resistance both ways, and it's identical; does this mean that there is no diode? i don't know.

basically, i would like some help figuring out how it works and why the power supply goes into standby. like, ask me to measure stuff, so we can conclude anything from it..
 

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rjenkinsgb

Active Member
#4
It's not really an "electronic lock", it is a solenoid-operated door strike.

With the rated voltage applied to the coil terminals, a solenoid (electromagnet) operates and allows the mechanism to release the door catch.

The power needs connecting to the four-screw end, the three-screw cluster is a switch for feedback.
The only reason I can see for the PSU overloading is if you connected to a switch contact instead of the coils?

If it is the one in that leaflet, the only way a diode could be involved is if it has an internal rectifier to convert AC to DC. That would not affect its operation on 12V DC, though if it's half wave it may only work on one polarity.
 

AL13N

New Member
Thread starter #5
but why is the resistance measured not fitting the mA that should be in there? and i did put it on the one that has that resistance, so that should be the solenoid, right?
 

rjenkinsgb

Active Member
#6
If there is an internal diode, that will mess up any meter readings as it takes 0.6V - 1.2V before any current is drawn.

If there were no diodes involved the coil connections should read about 60 ohms with the coils parallel or 120 ohms if they are in series.

Are you using a digital or analog meter?

Does it have a "diode test" range - see of you get different readings with that; it should give a high enough voltage to read across a bridge rec.

It's also possible the wires are damaged or pinched somewhere, if the gap behind the strike is not big enough?
It may be worth removing it and checking the resistance directly at the terminals & seeing what wires are where.
 

AL13N

New Member
Thread starter #7
i see...

i've measured using a simple digital meter. powered by 9V battery.

iinm there should be a diode setting, when you touch both ends towards each other, it beeps.

there is an pnp and npn thing, but i donno if there's something for a single diode... i'll have to check...
 

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