20 Applications for Security
10 Items Per Page
Constant Voltage System for Noise Masking and Overhead Paging
AN-2136
Description
Random white noise generated by the ST‑NG1 White and Pink Noise Generator is fed to Input 2 of the HD‑MA35A Mixer Amplifier. A Paging Source is connected to Input 1 of the HD‑MA35A. The Mixer Amplifier can be programmed to attenuate (duck) the white noise by 25dB during a paging event. Ducking can be initiated either manually, from a contact closure on the paging device, or automatically by adjusting the Input 1 VOX sensitivity on the HD‑MA35A. The ST‑NG1 is powered directly from the 24 Vdc output on the rear of the HD‑MA35A.
Aural and Visual Alerts at Security Station of Motion Detection By Zone
AN-2038
Description
This application uses a motion sensor in each of four zones to trigger a corresponding RDL D‑BZR Audio Alert Module at a security station. When triggered, the D‑BZR provides a loud alert tone and visual LED indication to identify which zone actuated the alert. The D‑BZR modules are mounted in a single DC‑4G tabletop chassis. During installation, the D‑BZR may be set for the normal (loud) alert tone level, or for a reduced level for use in a confined area. It may also be set to alert only for the duration the motion sensor is active, or to latch continuously in the alert condition upon motion detection. When triggered in the latching mode, the D‑BZR provides a continuous tone and LED indication until the front‑panel reset button is pressed.
Two-Zone Noise Masking System for Office Space
AN-2039
Description
This application shows the layout of a two zone noise masking system. The white noise line output from the RDL ST‑NG1 feeds the inputs of two RDL FP‑PEQ3 parametric equalizers. The FP‑PEQ3 equalizers allow the installer to flatten the noise spectrum in each zone. The line output of each FP‑PEQ3 is fed through RDL FP‑PA20A 20W, 70/100 V power amplifiers. The 70 V output of each FP‑PA20A feeds multiple 70 V speakers in its associated zone. Multiple equalizers and amplifiers may be added for larger systems with more zones.
Loudspeaker or Headphone Listening Station for Microphones Positioned in An Observation Room
AN-2223
Description
Two microphones positioned in the observation room are preamplified and mixed by the ST‑MX2 audio mixer. The line‑level output of the mixer is amplified by the D‑HPA3 3.5 watt power amplifier to feed a D‑SP1A Decora‑Style loudspeaker. The D‑HPA3 includes a separate headphone amplifier. The speaker amplifier is set (rear‑panel switch) to mute the speakers when headphones are connected. The front‑panel volume knob controls both the power amplifier and the headphone amplifier level. The high‑impedance bridging input on the D‑HPA3 allows the audio output of the mixer to also feed a recording device.
Remote Security Monitoring and Recording
AN-2056
Description
This system gives the user the ability to monitor and record audio from a remote location. The STM‑2 Microphone Preamplifier feeds both a recorder and a monitor amplifier in the monitoring location. The 2 Watt amplifier feeds a single 8Ω speaker in the room where the recording is taking place. The remote volume control gives the user the ability to adjust the volume as needed. The wall control is offered in RDL standard white/gray or in stainless steel with custom labeling available.
RDL FP-CH8 Provides Unique Annunciator For Each Door
AN-2037
Description
The RDL FP‑CH8 Chime Generator is the solution when it is necessary to associate a unique sound with specific events. In this example, four of the eight available chime tones are used. A particular chime identifies which doorbell button is pushed. The push button associated with each door triggers a specific chime in the FP‑CH8. The module’s line level audio output is amplified by an RDL ST‑PA2 audio amplifier so the chime is heard in the monitoring room. The FP‑CH8 output could feed audio to a facility‑wide BGM/paging system. A setting on the FP‑CH8 allows the chimes to duck or to be mixed with background music. The eight chime tones can be sampled by clicking “Hear me in action†on the FP‑CH8 product description page on the RDL web site.
Speaker Serves Dual Duty as Microphone and Speaker
AN-2021
Description
This intercom application reduces the hardware requirements for a secure or weatherproof call box like those found in drive‑through talkback systems or secured entryways. The ST‑IC1 Intercom Amplifier input accepts a dynamic mic or phantom powered condenser mic. It can also use an 8 Ω or a 45 Ω speaker as a microphone element. An ST‑LCR1 Logic Controlled Relay is used in this application to switch a remote speaker so that it can function alternately as a speaker and as a microphone.
Sequential Video Switching Provides Full-Screen Images From Four Monitored Zones
AN-2040
Description
RDL’s RU‑VSQ4 Video Sequencing Switcher provides sequential vertical‑interval (to eliminate/minimize screen roll) switching between (up to) four video cameras, pausing from one to fifteen seconds on each image. The sequence interval is adjustable on a recessed front panel control. The RU‑VSQ4 provides a loop‑through output from each camera to facilitate connection of additional monitors or recorders. The security agent can press any source pushbutton to continuously view that particular source, then press the button again to resume sequencing. Open‑collector outputs are provided on the rear panel for audio‑follow‑video switching, tally indicators or other control.
Distributed dc Power From Current-Limited Switching Power Supply
AN-2193
Description
The low current consumption of STICK‑ON modules allows multiple modules to be powered from a single supply. The ST‑PD5U distributes power from any RDL current‑limited switching power supply to up to five modules with a total current requirement of 2 amperes or less. RDL 24 Vdc switching power supplies (purchased separately) are available with current ratings of 500 mA, 1 A and 2 A. All meet ENERGY STAR Level V standards.
2-Zone Paging System for Office Space
AN-2063
Description
This example shows how to utilize telephone line (input) ports on an existing KSU to add two zones of paging from the telephone system. The ST‑TC1 acts as a virtual phone line when interfaced with a KSU FX port. When either “line†is selected using any phone instrument connected to the KSU, the associated ST‑TC1 provides an audio path from the instrument mouthpiece to the paging amplifier. In this example two FP‑PA20A 70 volt amplifiers are powering 70 Volt loudspeakers in the two office areas. The ST‑TC1 provides relay contact closures when it is activated by a telephone instrument. The relay contacts can be used to provide additional functions when paging is active, including visual indicators or triggering a radio transmitter.