Bypassing Automatic Sliding Door Locks

From The Mind of Gabriel Shear

Wednesday, February 11, 2015


Disclaimer: Information presented here is for educational purposes only. The author and website are not liable for any damages caused by the misuse of this information.


Suction CupSliding Glass Door



 How To Bypass Automatic Sliding Door Locks

The two items above seemingly have no connection to each other.  A suction-cup dent puller, and automatic sliding doors. At first glance totally unrelated. They do however have one special connection. We can use the dent puller to bypass the lock on the sliding glass door.

“So how exactly can you accomplish this?” You might be asking. Well thanks to life safety laws. Like the kind that require fire extinguishers and exit signs. Doors like the one pictured above can not stop people from leaving a building. It’s called free egress, and it’s meant to save lives.

Suppose a fire broke out in the store while people were still inside. Everyone’s gonna panic and run for the exits like it’s the new thing to do. Now suppose the fire caused a power outage and suddenly those power doors don’t open. As everyone crashes into the door trying escape those up front would be crushed.

To prevent that from happening, the glass panels the door is made up of are designed to break free, and swing outward if enough pressure is applied from the inside. Normally this wouldn’t matter from a security standpoint. As there are no handles or anything to grab on too from the outside. No way to pull outward.

In comes the dent puller. By applying the puller near the edge of one of the side panels you can now pull with enough force to cause it to release. The same as if someone was pushing from inside. Once the panel has released you now have access, and have bypassed the lock. Also due to the way the doors normally function, opening the door this way will generally not trigger any kind of alarm sensor tied to the door. Manufacturers have different designs, but almost all types have this feature. A little bit of MacGyver type knowledge to keep in mind.

– Gabriel Shear




Key-Switch Flaws

From The Mind of Gabriel Shear

Tuesday, July 1 2014


Why You Shouldn’t Use Key-Switches

KeyswitchI come across this type of setup quite often.

You’ve got an electronic access control system installed.Worried that one day your system might not work you decide you need key overrides (This defeats some main points of using electronic access control) While usually on doors that use electric latches, or in handle solenoid release mechanisms a normal keyed door handle to unlock the handle in an emergency is the norm. On the other hand, doors that use magnetic locks or other means not related to the normal method of opening a door require a different approach. Enter the key switch.

Like its name implies, this device contains a key cylinder and an electrical switch. When a key is inserted into the lock and rotated, a cam on the rear of the cylinder depresses a switch which is normally used to break power to magnetic locks or signal the access control system to release the lock. Regardless of the way in which it controls the door it still boils down to the fact that A KEY IS USED TO RELEASE THE LOCK!

Looking at the photo above you will probably notice to very immediate things. First the key-switch is easily accessible and second, it is attached using the very insecure security screws. If someone were to remove those two screws. This is what they would see on the other side of the key switch.Keyswitch backA switch mechanism which can easily be bypassed with one finger… One little finger!


Seriously, this is all that is required to bypass this high-end access control system. While not a fault in the system itself, this situation has none the less been created. Granted not all key-switches have this exact design. Some have the switch built into the cylinder. Still the purpose of the switch is to make or break an electrical circuit, and whether or not it has an exposed switch is beside the point. As long as the wires are exposed you can either open the circuit (cut the wire) or close it (short the wires together).

There are a few ways in which you can increase the security of key-switches.

Possible solutions:

Move the key overrides to a more central and secure location.

Install a local siren with a sensor (plunger or magnetic reed type) installed on the key-switch so as to draw attention if the device is removed. (Alarm must latch to on state once set off to be affective)

If using security guards. Monitoring of the access control system for alarms is an option.

Email notifications from the access control system are possible if available and responded to in a timely manner.

Generally in this setup the switch just disengages the locking mechanism but doesn’t inform the access control system that it has done so. Once the door is opened the system will set an alarm condition. Depending on the system and the response programmed, it may only log that information or set off a linked burglar alarm or local siren. It is usually the case that, do to the high number of alarm conditions triggered by normal everyday use, that not much is done to alert anyone of the alarms do to the nuisance factor. People generally are not very security conscious and convenience usually triumphs.

If you use, or are planning to install such a system, you have been warned! Criminals have this information and know the flaws!

– Gabriel Shear





Fume Extractor

From The Mind of Gabriel Shear

Thursday, June 26 2014


Fume Extractor

Disclaimer: Information presented here is for educational purposes only. The author and website are not liable for any damages caused by the misuse of this information by others.

This is a design for a fume extractor for removing the fumes while soldering electronics and other parts. It is simple, and yet effective at its job while being cheap and easy to construct. If you’ve ever done any soldering, you know that the fumes can be very noxious. Rosin flux smells fucking awful and isn’t to healthy to breath.

Below are the parts you will need:

Qty.               Part Description

1                   4x4x2 Plastic Electrical Junction Box

1                   12vdc Electric Fan (scavenged from old PC)

1                   12vdc Power Supply

1                   Power Switch

1                   Power Connector (optional)

2ft.                18 AWG Wire

1                    Pack of Carbon Air Filters ( one pack should last a lifetime!)

1                    4 Inch Strip of Self Adhesive Velcro


After you have gathered all the parts you will need, you can begin construction. The box was purchased for 6$ at a local hardware store along with the pack of carbon air filters for 9$. The rest was scavenged from old electronics.

All Parts

Start by cutting a hole in the back of the box as close to the size of the electric fan as possible. A 2 1/2 in. hole-saw was used on this one. Holes were also drilled to match the mounting holes of the fan.

Back hole

After mocking up all the parts to make sure everything would fit. It was found that the fan would have to be off-center to fit the other parts inside. A hole was drilled in the bottom right corner and a small file was used to square it up to fit the power connector which was then  glued in place. The Fan was then screwed to the box and the power switch installed on the top.

power connectorpower switch

After everything was mounted in the box polarity of the power connector was checked by plugging the power supply into it and checking with a voltmeter which pin was positive and which was negative. Everything was then wired together. The negative terminal on the power connector gets wired directly to the negative power leg of the fan. While the positive leg goes to one leg of the switch and from the other leg of the switch to the positive leg of the fan. This way the switch is breaking the power to the fan on the positive power leg.

power diagram

Once everything is connected, power it up to ensure that everything is functioning correctly and that the power switch is operational. A power cube from and old network switch was used. It was rated 12 vdc @ 1 amp of available current draw. The fan only uses .25 amps so this was plenty.

Next taking the front cover, a series of holes were drilled in to it. Four larger holes and one smaller center hole was found to fit nicely.  Four pieces of the Velcro were attached to the backside of the cover using the hook side of the Velcro and not the loop side. Next a piece of the carbon filter was cut to fit shape of the lid and stuck to the Velcro to hold it in place. Finally the plastic wings on the box were removed and the front cover was screwed back to the box and everything was tested once again.

front coverCarbon Filter

You now have a fume extractor to remove fumes while soldering. A useful tool to have.

finished unit


The power connector is optional, the power cable could be ran through a small hole and wired directly to the circuit. Tying a knot on both sides of the cable where it goes through the box would prevent it from pulling out or getting pushed to far in to the box, possibly getting caught in the fan.

-Gabriel Shear


Ugly Little Book

From The Mind of Gabriel Shear

Saturday, February 1 , 2014


uglys electricalUgly’s Electrical  References

I’ve been using this little book for over 10 years now. It’s served me well as a supplement to my more formal education. While I know most of what’s in it by heart now, I still keep it with me just in case.

Ugly’s Electrical Reference is an excellent reference for those looking to do more of their own electrical work. It contains many, many excellent charts, and instructions, etc.

So basically, they took all the knowledge that an old experienced master electrician would have, and compressed it down into this little gem. I use this book all the time and it saves me from having to search through the internet for vague charts and information I need, and since it’s a book its “End of the world, no internet proof” It’s that much more valuable.

I picked mine up at the local Home Depot for a little over five bucks many years ago. An excellent price for such an awesome information filled book.

A brief overview of the contents include:

Ohm’s Law

Information on electric motors and their wiring

Use of electrical transformers and calculations for loads

Wire charts and properties of various cabling types

Charts and information for all kinds of electrical tubing and conduit

Pretty much everything related to electricity and its uses

So as I hope you can see. This is a book you need to own. So go get one, and have the confidence of knowing you can have the knowledge of a master electrician in your back pocket.

– Gabriel Shear