Battery Power - Battery Power Circuits |
by Paul Norton
SINGLE BATTERY PACK CIRCUITS
The most common circuit found in battery power and radio control applications uses a switch to toggle an on-board battery pack between its charging plug and a radio receiver. The following illustration shows the components used to build this simple circuit for use in a trailing power car.
An Aristo-Craft, lithium-ion battery pack is connected to the center terminals of a double-pole double-throw (DPDT) center-off switch. A battery charging plug is soldered to the left terminals, and the input wires of a 27 MHz, Train Engineer (TE) receiver to the right terminals.
Toggling the switch one way connects the battery pack to its charging plug.
Toggling the switch the other way connects the battery pack to the receiver.
Adding an MU plug to the output terminals of the TE allows any Aristo-Craft, Plug and Play locomotive (or any other locomotive with an MU plug added and its track power pick-ups unplugged) to be battery powered and radio controlled using this simple circuit in a trailing power car.
NOTES:
- Aristo-Craft, lithium-ion battery packs are rated for 2 amps and have a built-in circuit board to protect them from heavy use or rapid charging. Heavy use and rapid charging could not only shorten their life, it could result in serious damage. Always use the proper charger when replenishing these battery packs.
- As the lithium-ion battery pack is only rated for 2 amps, the fuse in the TE receiver should be replaced with a smaller 2.5 amp or 3 amp fuse.
- It is not necessary to solder the battery pack wires directly to center terminals of the switch. The male connector of a 2-pin plug set can be soldered to the switch instead, and the battery pack just plugged into the connector.
The 2-pin plug sets and DPDT, on-off-on, mini-toggle switches are available from All Electronics under catalog numbers CON-240 and MTS-12 respectively.
Ottawa Valley GRS members can purchase these components by contacting Paul Norton. See the Items For Sale Section for details.
This same circuit can be used to provide on-board battery power and radio control in Plug and Play locomotives by replacing the large 27 MHz TE receiver with an Aristo-Craft 2.4 GHz TE receiver.
The switch can not be soldered directly to the receiver however, as the receiver is mounted in the Plug and Play socket. To connect the switch, the locomotive's redundant MU plugs are unsoldered and removed. The wires from the right terminals of the switch are then soldered to the engine's circuit board in place of one of the MU plugs.
NOTE: Modern Aristo-Craft, Plug and Play diesels have polyfuses to protect their internal electronics. These are the square yellow devices shown in the above picture. If you are installing on-board battery power and radio control in locomotives without polyfuses, a fuse should be installed in the positive wire between the switch and the receiver.
TWIN BATTERY PACK CIRCUITS
For heavy locomotives or double-headers that may exceed the 2 amp limit of one Aristo-Craft, lithium-ion battery pack; a trailing power car with two packs is required. Unlike Gel Cell, Ni-Cad or NiMH battery packs, Aristo-Craft lithium-ion battery packs must be wired in parallel, not in series, and charged separately.
To accomplish this a standard, four-pole double-throw (4PDT), center-off switch is used. The 4PDT switch has 12 screw terminals. To make the wiring easier to understand the terminals have been divided into three columns for the charging plugs, the battery packs and the TE receiver.
Number 6 stud, loop terminals are soldered to the ends of the wires of two charging plugs, and fastened under the screws of the LEFT column of terminals as show in the following illustration.
Number 6 stud, loop terminals are soldered to the ends of the wires of two lithium-ion battery packs, and fastened under the screws of the CENTER column of terminals as show in the following illustration.
The two negative terminals in the RIGHT column of the switch are joined to the negative input wire of a 27 MHz receiver using a jumper wire as shown in the following illustration.
To prevent power from passing from one battery pack to another, diodes are installed on the positive terminals. The diodes will only allow the power to pass through them in one direction to the receiver.
Toggling the switch in one direction will connect the battery packs to the receiver.
When the switch is toggled in the other direction the receiver is disconnected, and the battery packs are separately connected to their charging plugs.
Adding an MU plug to the output terminals of the TE, allows any large, Aristo-Craft Plug and Play locomotive (or any other locomotive with an MU plug added and the track power pick-ups unplugged) to be battery powered and radio controlled using this circuit in a trailing power car.
NOTE: As each lithium-ion battery pack is only rated for 2 amps, the fuse in the TE receiver should be replaced with a smaller 5 amp fuse.
Replacing the large 27 MHz TE receiver with an Aristo-Craft 2.4 GHz TE receiver allows the circuit to be used on-board Plug and Play diesels and steam locomotives.
The switch can not be soldered directly to the receiver however, as the receiver is mounted in the Plug and Play socket. To connect the switch, the locomotive's redundant MU plugs are unsoldered and removed. The wires from the diodes and the negative terminal of the switch are then soldered to the engine's circuit board in place of one of the MU plugs.
NOTE: Modern Aristo-Craft, Plug and Play diesels have polyfuses to protect their internal electronics. These are the square yellow devices shown in the above picture. If you are installing on-board battery power and radio control in locomotives without polyfuses, a 5 amp fuse should be installed in the positive wire between the diodes and the receiver.
The 4PDT switch and diodes are available from All Electronics under catalog numbers STS-71 and 1N5822S respectively.
Ottawa Valley GRS members can purchase these components by contacting Paul Norton. See the Items For Sale Section for details.
For more detailed information on how these circuits are used, refer to the articles in the Battery Power and Radio Control Section.
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From David McCurdy [76.69.19.109] - 5/3/09 3:21 PM
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Last Modified 10/8/09 9:57 AM