Tuesday, 17 January 2017 12:09

The Benefits of a Regulated Power Supply

Did you know something as simple as output voltage can have a dramatic effect on the life of your locks?  All LifeSafety Power FPO power supplies are UL Listed as having a regulated output, extending the life of locks and other connected equipment by reducing heat.  In order to explain how this is possible, we first need to ask...

What Does "Regulated" Mean?

The word "regulated" can have at least two different meanings when talking about power supplies.  These two meanings are very close, with one distinct difference. 

In engineering terms, a regulated power supply is one which has circuitry to hold the output voltage within a small range that is centered around the actual SET output voltage across all line and load conditions.  This window is usually small and given in a +/- percentage (for example:  27.2V +/-5%).  This example power supply can range between 25.8V and 28.6V and still be considered a properly regulated supply.

In the lifesafety industry, UL defines a regulated output as +10%/-15% of the NOMINAL voltage.  In this case, the power supply set for 27.2V is considered to be a 24V power supply.  Given the +10%/-15% requirement on this 24V nominal voltage, this translates to an acceptable voltage range of 20.4V-26.4V.  In this case, the 27.2V power supply is NOT considered to be regulated by UL, even if that voltage doesn't change at all under any line or load conditions.

As you can see, the subtle difference between set voltage and nominal voltage makes a significant difference in what is considered regulated.  From a strictly electronic engineering standpoint, essentially every DC power supply in the industry today is regulated - however from UL's perspective, very few are considered regulated.  For the remainder of this discussion, "regulated" refers to the UL definition.

How Does a Regulated Supply Help My Locks?

So how does this lower voltage range extend the life of a magnetic lock such as a maglock or door strike?  Simply by reducing heat.  Lowering the voltage used to power the lock greatly reduces the heat generated within the lock and is recommended by most lock manufacturers.  Excessive heat within the lock can cause the windings to break down prematurely and can also cause mechanical failures due to expansion or swelling of internal components.  Minimizing heat is especially critical in warmer climates, where it is not uncommon for a strike to "jam" up due to heating effects of the higher voltage coupled with strong afternoon sunlight or higher ambient temperatures.

Can't I Just Adjust the Voltage Down?

Many "Brand X" power supplies do have an adjustable output voltage allowing a wide adjustment range.  While it's true that the output can probably be adjusted to a low enough voltage to protect your locks on these supplies, the problem then comes in properly charging batteries.

A non-regulated power supply has a single regulator and uses the output voltage to also charge the batteries, usually through a current limiting device like a PTC (which has its own set of problems).  This is done by many manufacturers to save the cost of an independent battery charging circuit.  The problem is that whatever the output voltage is set for is also what is applied to the batteries - so if you set your output for 25VDC, your battery charging voltage will also be only 25V, which is far too low to charge a 24V lead-acid/gel cell battery set.  Increase the output voltage to the recommended 27.2V to charge the batteries and you are now applying excessive voltage to the locks.

So What is the Solution?

LifeSafety Power has gone the extra mile to provide an independent charging circuit on all of our DC power supplies.  This allows the main output voltage to be set for 25V to power your locks and other equipment while a separate regulator charges the battery at the proper 27.2V nominal voltage.  This also has other benefits, such as the battery charging current not reducing output current capability, a stable output voltage during battery recharge, larger battery capacity, and optimized battery charging (so not only do your batteries charge properly, they also charge faster).

The output voltage setting of 25V was chosen as a balance between being low enough to minimize excessive heat while also being high enough to provide a small overhead for overcoming a reasonable voltage drop in the wiring to the powered device.  At the 12V setting, the output voltage is set for 12.5V.

Hopefully you now have a clearer understanding of what "regulated" means, how it can help you, and yet another benefit of LifeSafety Power.  If you have any questions on this topic or need any other assistance, our This e-mail address is being protected from spambots. You need JavaScript enabled to view it department is here to help.

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In previous parts of this series, we have covered the basics, inputs, outputs, and jumper configuration of the C8 board.  If you missed any of these parts, you can find them here:

Part 1 - Power and LEDs
Part 2 - Inputs
Part 3 - Outputs
Part 4 - Jumpers

In this, the final part of the series, we will explain the usage of our Excel Jumper Configuration Tool.

About the Tool

The C4/C8 Jumper Configuration Tool is available free for download from the LifeSafety Power website's Calculators page, or by clicking here.

The tool uses information entered by the user to determine the correct jumper settings.  Even if you have the jumper settings memorized, the tool is very helpful in quickly configuring multiple zones.  Jumper settings can be predetermined in the office, printed, and included in the system design documentation, or done on-the-fly at the job site.

Using the Tool

To begin, open the file in Excel.  There are three sections on the screen - Voltage Sources, Zone Information, and Results.

Main Screen

Step 1 - Voltage Sources
The Voltage Sources section is where you enter the B1 and B2 voltages used as the power source for the C8.  In a single voltage system, only the B1 field will have information entered.  The B2 field should be left blank.

A dual voltage system should have both the B1 and B2 fields filled in as appropriate.  Remember that a dual FPO system (as built by LifeSafety Power) would have the top FPO's voltage in the B1 space and the bottom FPO's voltage in the B2 space.  An FPO/B100 system would have the FPO's voltage as B1 and the B100's voltage as B2.

Entering this information correctly is important for the yellow jumper's setting.  Reversing this data will cause the incorrect output voltage to be placed on the outputs, potentially damaging the powered equipment.  Remember to always double check your output voltages before connecting any load devices.

The B1/B2 information will remain consistent across all boards and zones in a typical FPO power supply system.

Step 1

In this example, the B1 supply is set for 24V and the B2 supply is set for 12V.

Step 2 - Zone Information
The Zone Information section is where you enter the information for the zone being configured.  This information may vary zone to zone.

  • Input Type - This drop-down selection allows you to choose the type of input connected to the input terminals for the zone.  Selections include NO or NC contact, remove or apply voltage, open collector, or no input.  The NO or NC contact selections are the most typical input types and would be used for a relay contact, pushbutton, etc.  The remove or apply voltage settings would activate the zone when a voltage is either removed from or applied to the B terminal of the input.  Open collector would be the setting to use for a transistor output, and "no input" would be the selection to use if you wanted a constant voltage output without input control.
  • Output Type - This drop-down selection allows you to choose the output type for the zone.  Selections include mag lock, fail safe or fail secure strike, NO or NC relay contact output, or constant output.  Choose the closest match for the output type needed (i.e. for an electrified handleset choose fail secure strike, since the operation is very similar).
  • Output Voltage - This drop-down will be populated with the values entered in the B1 and B2 fields in the Voltage Sources section above.  Select which voltage is desired for the zone.
  • Zone FAI? - This drop down has two selections - yes or no - to select whether the zone should react when an FAI is received on the FPO power supply.

Step 2

In this example, the input is set for a NO Dry Contact and the output is set for a 24V maglock with FAI.

Step 3 - Results
The results section displays the correct jumper settings for the configuration entered in steps 1 and 2.  Jumpers A-F are shown with a visual representation of positions 1 and 2 for each jumper.  Remember to look closely at the C8 PC Board for positions 1 and 2 for each jumper carefully, as these positions change from jumper to jumper.

Step 3


I hope this series has been useful to you and has helped you to become an expert in using the C8 family of lock control boards.  If you need any assistance, our This e-mail address is being protected from spambots. You need JavaScript enabled to view it department is here to help.

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Wednesday, 07 October 2015 14:11

Understanding the C8 Board - Part 4 - Jumpers

In previous parts of this series, we have covered the very basics and the inputs and outputs of the C8 board.  If you missed these parts, you can find them here:

Part 1 - Power and LEDs
Part 2 - Inputs
Part 3 - Outputs

This week we will cover in detail the jumper configuration of the C8 board.

General Jumper Setting Information

First, it is important to verify the voltage of the power supplies and to set the C8 jumpers before connecting any load.  This is to ensure the proper voltage is sent to the load devices and prevent damage to the devices.  Verify output voltage on each zone before connecting any load.

If you have read the previous parts of this series, you should have a fairly solid understanding of how the C8 should operate.  This knowledge is helpful in setting the jumpers when a manual is not available.  As mentioned in previous posts, it is not necessary to have the function of each jumper's positions memorized - only the overall function of the jumper.  For example, once you know the Red jumper is for FAI, you know that is the jumper to move if FAI is not operating the way you expect it to for a particular zone.  There is no need to memorize that Position 1 is on, and position 2 is off, or that position 2 of the Blue jumper is for a NO input.  As you go through the following sections, take note of the jumper color in relation to its function.

Also remember the correct LED operation - LED lit steady for a locked door, and flashing for an unlocked door.  The goal is to get this correct with relation to the input, then set the output to operate correctly.

Finally, please note jumper positions as they are printed on the PC boards carefully for EACH jumper.  For some jumpers, position 1 is up, while for others, position 1 is down.  Every jumper has a position marker next to it.

Black Jumpers

The black jumpers select whether the output will be a relay contact output or a wet (voltage) output.  Both jumpers should always be set in the same position, without exception.  Use caution when setting these jumpers, as position 1 is different on each jumper.  From the factory, these jumpers come set in position 2, which provides a voltage output.  If a relay output is desired, move these jumpers to position 1.

Yellow Jumper

The yellow jumper selects the voltage to be applied to the zone's output.  Position 1 sets the output to the B1 voltage, and position 2 sets it for the B2 power supply.  In a single voltage system, this jumper will remain in position 1, as there is no B2 voltage present.

In a dual FPO system, as built by LSP, the top FPO will be the B1 voltage.  The bottom FPO will be the B2 voltage.  So if the top power supply is set for 24V and the bottom FPO is set for 12V, then position 1 on the yellow jumper will set the output for 24V, position 2 for 12V.  In an FPO/B100 system, the 24V is on B1, and the B100's output is on B2.

Again, always verify each zone's output voltage before connecting any load to the C8.

Blue Jumper

While all of the jumper settings are equally important, getting the blue jumper set properly is critical to the operation of the C8.  In Part 2, we discussed how the B terminal of the input is a voltage input, while the A terminal is a voltage source.  The blue jumper sets the zone to either activate on the application of voltage, or the removal of voltage on the B terminal.

Position 1 will activate the zone on a removal of voltage from the B terminal.  This is the setting you would want for a NC contact activation.  The NC contact will normally connect the voltage from the A terminal to the B terminal.  When the NC contact opens, the voltage at the B terminal goes to zero, and activates the zone.  This is also the setting to be used for an open collector input - normally, a voltage is present on the B terminal, and the open collector will shunt this voltage to zero to activate the input.

Position 2, is the opposite - an application of voltage will activate the zone.  This is the setting to use for a normally open contact activation.  When the contact closes, it connects the voltage from the A terminal to the input of the B terminal to activate the zone.

To verify the proper setting of the blue jumper, look at the LED status for the zone in relation to the input.  If the LED is flashing when the input is set to unlock the door, the blue jumper is set correctly.  If the output is operating opposite from what is expected, but the LED is operating correctly, then the white jumper needs to be adjusted.

White Jumper

The white jumper sets the output by selecting the NO or NC contact of the internal relay contact.  Position 1 uses the NC contact and position 2 uses the NO contact.  When set for a relay output, this is straightforward.  When set for a voltage output, position 1 should be used for a doorstrike, electrified handleset,  or other fail-secure device.  Position 2 would be used for a maglock or other fail-safe device.

If the output is operating backwards from what is expected but the LED is indicating correctly with relation to the input, the white jumper should be changed.

Red Jumper

The red jumper sets the FAI activation of the zone.  Position 1 enables FAI activation, while position 2 deactivates FAI for the zone.  The setting of the blue jumper is crucial to proper FAI operation.  Remember that the LED for the zone should flash when the door is unlocked.  If the blue jumper is set incorrectly, the LED will be flashing when the door is locked.  This presents a problem when an FAI activation is received because the C8 thinks the door is already unlocked, so the output does not change.  If the LED is operating backwards from what is intended, move the Blue and White jumpers to the opposite position that they are currently in and FAI should begin working properly.

Settings Chart

The manual for the C8 board has a very helpful chart for jumper settings.  The Common Jumper Settings chart is organized by output type.  Find the desired output type, then look down to find the desired input type.  Then select With or without FAI and look across the row for the jumper settings for that configuration.  This chart covers 99 percent of common applications.

Next Week

Next week we will cover the usage of our Excel-based C8 Jumper Configuration Tool for help with jumper settings.  Until then, if you need any assistance, our This e-mail address is being protected from spambots. You need JavaScript enabled to view it is here to help.

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