Old Federal Signal Siren Control Timers
Early Type Federal Signal Siren AR and AF Timers
This timer is the early version of the Federal AR timer. The Federal timers used clock timer motors which operate a system of cam-operated switches to activate the siren signals for a 3 minute cycle. The type of timer pictured above was sold by Federal up through some time in the 1960's. I base this on a drawing in the early issue of the Thunderbolt siren manual that shows siren hook-up wiring diagrams. The date on this drawing is 1968 and it shows the newer style (shown below) siren timer.
The timer pictured was installed in Dallas Texas in 1959. The box measures W12.5 inches x H9.5 inches x D6 inches. The red lamp above the buttons activates only when the timer is cycling.
The top button on the front panel is the "Manual" button which operates the siren for only as long as the button is depressed. This is the same function as the "test" button used on later model Federal timers.
The second button from the top is the "Take Cover" signal which operates the siren in a on-off or wavering mode for 3 minutes. On later timers this function button is labeled "Attack."
The bottom button is the "Alert" signal which operates the siren in a steady "on" mode for 3 minutes. On later timers this function has the same name.
This is the inside of the early version of the AR timer pictured above. You can see in this picture that the timer uses mechanical switch levers which are activated by a series of cams moved by the timer motor. The purple wires at the bottom are connected to the power input terminals of the terminal strip. This timer operates on 230 volts. The Federal electro-mechanical timers are simply timed switches. They don't output any power so it's not possible to power a siren or relay from the timer itself.
This is an early Federal AF timer. The timer box is the same size as the AR timer pictured above but the AF timer has the added mode to operate a "Fire" signal. The Fire signal was used on the Federal Thunderbolt 1003 and Federal 3T22 sirens for the option to also use a Civil Defense siren as a volunteer fire department call-in siren. The fire circuit in the AF timer would activate a cycling switch in the RCM 3 control cabinet (Thunderolt) or the RC6 (3T22) which would operate the Hi-Lo signal of the siren. An explanation of the fire signal operation is shown on the Federal Siren Pictures page.
Inside the early AF timer is pretty much identical to the early AR except for the additional cycle cam wheel, switch, extra push button and relay for the fire signal circuit. The switch levers with rotary cams beneath are a bit easier to see in this photo. The timer motors in these early timers are 120 volt and the voltage is reduced with a large load resistor. The resistor is the brown tube-like component next to the timer motor in the AR and AF timer inside photos.
Later Type Federal Signal Siren AR and AF Timers
This is the later version of the Federal AR timer.
Federal Signal no longer sells this timer but when it was available they
listed for about $1500.
This particular timer has NOV 1986 stamped inside. The box measures
W8.5 inches x H10.5 inches x D4 inches.
The yellow lamp on the front of the box operates as long as the unit has
power and the red lamp operates when the timer is cycling. This timer has
the same functions as the early timer but the front panel is quite a bit
different.
The silver button on the front panel is the "Test"
button which, like the "Manual" button on the early timer, operates
the siren for only as long as the button is depressed.
The blue button is the "Alert" signal which operates the siren in a steady ON
mode for 3 minutes.
The yellow button is the "Attack" signal which
operates the siren in a on-off or wavering mode for 3 minute signal.
The black button is the "Cancel" button which stops the timer's
control of the siren signal while the timer continues to run to the end
of it's cycle. The early timers didn't have the cancel feature.
For more in-depth information on these timers I have the Federal instruction sheet for the later siren times available for download here... Instructions For Models PGA, AR, AF, AR5 and AF5 Timers.
The inside of the later Federal AR timer is quite a bit different but the same principal as the older AR timer but with newer more compact components. The later timers used smaller rotary cams and microswitches instead of the much larger lever switches. A transformer was also added so the timer could be connected to 120 or 240 volts. These timers could also have transformers in them for connection to high voltage supply.
Like the early AF timer the later AF timer has the added "Fire" button on the front. The "Fire" signal would be used as a fire call signal for volunteer firefighters. The fire signal is similar to the attack signal in that the siren turns on and off resulting in the up and down signal but also produces a "Hi-Lo" signal while the siren is powered during the on portion of the on-off cycle. When the siren runs in the off portion of the signal the Hi-Lo stops and the siren coasts down regularly. The Federal Thunderbolt 1003 and the Federal 3T22 were both capable of producing the fire signal. An explanation of the fire signal operation is shown on the Federal Siren Pictures Page.
This timer is pretty much the same as the AR timer above but has an additional motor-driven cam and relay to operate the fire signal. The hook-up schematic is missing from this unit.
Federal PGA Timer
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Federal also made a PGA timer which stands for Predetermined General Alarm. This is the description from the Federal timer instruction sheet. The PGA (Predetermined General Alarm) is primarily used for general alarm sirens, allowing them to sound an up and down scale wailing signal for a predetermined time. The standard PGA timer produces a timing of 8-seconds ON, 4-seconds OFF; repeated 10 times in a two minute cycle. I don't know how long Federal made the PGA. The date on this timer is AUG 23 1974.