Tech Tips: Timers and Switches

May 2, 2018
This month’s challenge is to enable remote operation of a vehicle gate whose logic control board got hit by lightning

This month I want to monitor a vehicle gate’s position, and send a pulse wirelessly to a remote location for purposes of monitoring and control.

I’ll use a variety of professional electronic security products readily available from distribution, direct from the manufacturers, and also on the Internet.

Although I’m all about saving money, I also value relationships with my suppliers, and want to reward them for having products and tech support available when I need it; just like I want my clients to reward me for my craftsmanship and expertise with their loyalty.

This circuit uses a heavy duty gate position sensor to activate an isolation relay which triggers a one shot pulse to a RF transmitter.

The purpose is to open a gate whose logic control board got hit by lightning. The logic control board can still operate the gate from a momentary trigger and charge its battery, but not much else. The homeowner turned down my quote for a replacement logic control board, but instead liked my offer to salvage the wounded control board with some Tom Swift Jr. engineering.

(If you do not know who Tom Swift was, Google it.)

If you do not know how to connect up the items I mentioned, please email me at the Locksmith Ledger and I’ll provide you with a schematic.

BEA RD-900 Receiver

The BEA Model RD-950 is a digital receiver and industrial transmitter with frequency hopping, sequencing and extended hold functionality.

Although it is designed to be used in conjunction with logic modules, but it’s wise to add isolation relays when controlling electric strikes and electromagnetic locks to protect the on board circuitry and avoid intermittent operation due to electrical noise.

Using a isolation relays is generally a good idea.

The BEA RD-900 receiver is small and has handy LEDs to help with programming and troubleshooting.

Specifications:

Frequency: 908-918 MHz (frequency hopping)

Emitted radio power: -25 dBm (TX)

Power consumption: 13 mA (Transmitter); 40mA (Receiver)

Supply voltage: 12-24 VAC/DC

Contact rating: 1.0 A @ 30 VDC; 0.5 A @ 125 VAC; 0.3 A @ 60 VDC

Temperature range: 14°F to 131°F (-10°C to 55°C)

Programmable units per receiver: 75

LEDs: red (receiver learn); blue (relay activation); tri-color (signal strength)

Dimensions: 2.5” (W) x 2.0” (D) x 0.75” (H) [RD900]

1.5” (W) x 3.0” (D) x 0.5” (H) [Transmitter]

Transmitter Protection Rate: NEMA4 / IP65

Certification: FCC, IC

Additional features include pulse mode, toggle mode, selectable .5- or 10-second hold time standard or extended hold signal strength meter

BEA Pushbutton Transmitter

The BEA 10TD900PB 900 MHz digital flag connector transmitter is intended for use with activation pushplates and requires two AAA batteries.

Although this transmitter is usually for use with “Knowing Act” door operator actuators, you can easily connect this unit to any external equipment with dry contacts. Instead of using batteries get a 3 Volt DC wall wart as a battery eliminator.

More Info: www.beasensors.com

Altronix 6062 Timer

This multipurpose timer does not have a real time clock, so it is not appropriate for events (actuating on a time of day and day of the week based routine) but the 6062 can do just about anything else.

This timer is suitable for many functions that require a timed operation: e.g. Access Control Applications, Siren/Bell Cut Off Module, Dialer Delay, Guard Tour Supervisory Timer, etc.

Some optional functions include: One Shot, Delayed Release, Delayed Operate, Delayed Pulse and Pulser/Flasher. You can set it to trigger of a contact closure or opening and if it triggers on the leading or trialing edge. Keep this module on hand and you will always be on time and have an ace up your sleeve.

Input: 12VDC or 24VDC operation is selectable.

Current Draw: Stand-by: 3mA, Relay energized: 40mA.

Relay: Selectable relay activation. One-second momentary relay activation at the end of the timing cycle enables the 6062 to provide the functionality of two timers.

Features:

  • Triggers via positive DC (+) voltage, dry contact closure, or removal of contact closure.
  • Quick and extremely accurate time range adjustment from 1 second to 60 minutes.
  • Built-in reset feature which cancels timing cycle.
  • Repeat (flasher/pulse) mode.
  • Visual Indicators. LED indicates relay is energized.
  • Temperature: Operating: 0° C to 49° C (32° F to 120° F).
  • Storage: - 20° C to 70° C ( - 4° F to 158° F).

 More Info: www.altronix.com

GRI 4400 Series

George Risk Industries (www.grisk.com) has a wide assortment of products designed for the security professional. They recently acquired another specialty manufacturer Labor Saving Devices. 

GRI's 4400 Switch Series is a heavy duty surface mounted industrial grade contact. Its weather resistant rugged aluminum housing and a variety of optional mounting brackets make it ideal for manly applications where rugged functionality like securing chain link gates, overhead garage doors, safes or walk-in freezer doors trumps being inconspicuous.

Discretion is not in the #4400 feature set. It is possible to install this device in a secure and attractive manner if desired to make it less prone to attack.

Kits include hardware, brackets and mounting instructions.

Features:

  • Lifetime Warranty
  • UL and ULC approved
  • Armored or jacketed cable
  • Standard gap up to 2 1/2"+
  • DPDT gap up to 2 1/2"
  • 3' standard lead length
  • Weather resistant aluminum housing
  • Ideal for securing chain link fence
  • Longer leads or jacketed cable on request
  • Variety of optional mounting brackets available
  • Switches or magnets are available separately
  • Supervisory loops available

Altronix RBST Relay Module

Altronix RBST relay is designed for continuous duty. It is rugged and dependable relay will handle many switching applications.

Input Voltage: 6VDC, 12VDC or 24VDC operation.

Current Draw: 30mA.

Contact Rating: 1A/120VAC or 2A/28VDC DPDT contacts.

Dimensions (L x W x H): 2.75” x 2” x 1” (69.85mm x 50.08mm x 25.4mm).

Weight: 0.15 lbs. (0.06 kg).

Weather: Operating -25ºC to 55ºC (-13ºF to 131ºF); Storage -25ºC to 70ºC (-13ºF to 158ºF); Relative Humidity 85% +/-5%.

Altronix RB524 Relay

RB524 relay module is designed for continuous duty. This rugged, reliable and dependable relay will handle many switching applications which control heavier loads like electromagnetic locks and electric strikes.

Input Voltage: 24VDC operation.

Current draw: 40mA.

Contact Rating: 5A/220VAC or 28VDC DPDT contacts.

System AC input VA requirement: 9.6VA.

Operating Temperature: -25ºC to 55ºC ( -13ºF to 131ºF).

Storage Temperature: -25ºC to 70ºC ( -13ºF to 158ºF).

Relative Humidity: 85% +/- 5%.

About the Author

Tim O'Leary

Tim O'Leary is a security consultant, trainer and technician who has also been writing articles on all areas of locksmithing & physical security for many years.