Introduction : Automatic signalling is used by most railways throughout the world to prevent two trains from travelling toward each other on a single line and to maintain a safe distance for a train following behind, should the lead train come to a stop for any reason. The SMRH Automatic signal packs provide the realism of signals that change from green to red as a train travels past them simulating block signaling. Similar circuitry is also used to activate level crossing alarms.
Automatic signal packs (ASP) : Supplied as a pack containing 2 x LED colour signals, 2 by 3mm LED size track detectors, and circuit board. Voltage input either 15-18VAC or 12VDC. The principal operation of the auto signal circuit is the special latching relay. The relay is latched and unlatched by track detectors that are light sensitive. As a train passes over them, the shadow created triggers the relay. Signal 1, was green and changes to red and stays in this position until the next detector is triggered beside signal 2 further along the line. This resets the relay which changes signal 1 back to green and signal 2 is now at red. The realism of block signals operating is at its best when the two signals are evenly spaced apart on a given line. As supplied, these packs are ready to run for trains running consistently in the same direction, eg, double main line. For single line running or point to point layouts, where trains are required to run in both directions past the signal, the optional dual over-ride module is available. This is incorporated into the circuit to lock signals at red whilst trains running in the opposed direction to the signal.
A variety of signal styles are available in the ASP packs: 2 colour single searchlight or 2 aspect green over red in N gauge and HO. Click on the part no. links to view the various signals supplied in the packs.
ASPH2100 : Auto signal pack supplied with 2 x HMA2100 2 aspect signals for either HO or OO gauge modelling
ASPH2160 : Auto signal pack supplied with 2 x HMA2160 single searchlight signals for HO gauge modelling
ASPH100 : Auto signal pack supplied with 2 x HMA100 2 aspect signals for N gauge modelling
ASPH160 : Auto signal pack supplied with 2 x HMA160 single searchlight signals for N gauge modelling
Automatic signal module only : Part No. ASMBP. This pack only contains the detectors and circuit board for those making their own Bi Pol LED type signals. Voltage input: either 15-18VAC or 12VDC.
Dual over-ride module : Part No. DOMBP. The dual over-ride module is designed for use with the auto signal packs to facilitate reverting signals to red when trains are run opposed to the signals on single lines or point to point layouts. The DOM circuit monitors track polarity to determine the train direction. The track polarity monitoring function is fully automatic for 12VDC power control.
Yard departure signal pack OO/HO : Part No. ASPYDP This circuit provides the automation of a green departure ground light lit up only when the points ahead are correctly set and the correct polarity is applied for a train to depart toward the signal. For reverse movements on the road or the points not set, the ground light remains at red. The circuit requires connection to an accessory switch activated by the points ahead of the departure signal. The track polarity function is fully automatic for 12VDC power control. Voltage input: either 15-18VAC or 12VDC.
Protect the section signal pack : Part No. PSPH2160 This circuit protects a section of single track between two stations by having 2 colour single searchlight signals govern the entry at both stations. The signals supplied in this pack are the HMA2160 type. The circuit detects track polarity to display correct signal aspects. Voltage input: either 15-18VAC or 12VDC. See diagram for signal aspects displayed releavnt to train positions.
Protect the section add signal and add detector modules : Part No's PSAS and PSAD. Add on modules to allow dual signals to function as departures from both a main line and loop. This module also looks at the direction of the points via a contact switch to cycle the correct detector and signal. Power input is from the "Protect the section module".
Auto level crossing packs : Supplied as a pack containing set of flashing crossing alarms, flasher unit, 2 x detectors and a circuit board. This circuit provides the realism of activating level crossing alarms automatically as a train approaches from either direction. The circuit board outputs 12 Volts DC to switch on a flasher unit. The relays latch and unlatch by light sensitive track detectors. The circuit also monitors track polarity to determine which sensor to trigger the flasher unit for the direction of the train. The track polarity function is automatic for 12VDC power control. Voltage input: either 15-18VAC or 12VDC.
LCPH2107 : Auto level crossing pack supplied with 1 x HMA2107 Crossing Alarms set and HMA 110 flasher unit for OO & HO modelling.
LCPH107 : Auto level crossing pack supplied with 1 x HMA107 Crossing Alarms set and HMA 110 flasher unit for N Gauge modelling.
Auto level crossing module only : Part No. LCM : This pack only contains the detectors and circuit board for those making their own crossing alarms and flasher unit etc. Voltage input: either 15-18VAC or 12VDC
LCMAD module : Part No LCMAD This circuit is for use in conjunction with the Auto Level Crossing Module (LCM or LCM pack) to provide the facility to install an additional detector on a loop track that either joins the main line before or just after the crossing. The module requires connection to an accessory contact switch activated by the loop to main line points to enable the LCMAD to determine which detector is required to activate the LCM.
Double track level crossing system : See diagram for components required to make up a fully automatic operation.
For individual signals and level crossing alarms in N HO & O scale including Reed switch activation units : Click on The HMA brochure
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