12 volt power supply and DC UPS for use in cars, 3 amp Automotive battery backup system. 12 volt DC UPS module keeps 12 volt equipment alive in cars and taxis using an external sealed lead acid battery.		Click here for 5 amp version with status output Click here for the 10 amp version. Click here for the 24V 10A car UPS controller
	This is what is inside the potted module This little gadget solves several problems for electronics in cars. First it allows you to charge an external lead acid battery from the car's electrical bus. Second it isolates the extra battery from the car so it won't be discharged by the car electronics, and it won't try to participate in starting the car. Third it powers your equipment in the car using the car electrical system, but switches to external battery power when the car's battery is stolen, or drops below a predetermined voltage. Fourth, it prevents the external battery from being overdischarged, keeping it from being damaged. Fifth, it prevents your equipment from running the car's battery down so the car can't be started. In one configuration it cuts off the car's battery when the voltage gets below 13.1 volts, then switches over to the external battery, in other words it switches over to the auxiliary battery when the engine is shut off and the alternator stops. In another configuration the crossover voltage is lower, say 12.0 volts. This allows your equipment to run off the car's battery but cut off while the car's main battery still has enough power to safely start the engine. To solve these problems we invented this automotive uninterruptible power supply control module, or car battery backup system. The idea is that you can connect the module to the car's electrical bus and it will charge an external 12 volt lead acid battery of your choice. Your equipment, which can be a small computer, telemetry equipment, or a car alarm, is connected to the module. This equipment runs off the automobile's electrical bus until the voltage of the bus drops below a preset voltage, the "N" voltage (from 13.1 to 11.9 volts, depending on your needs). Then the external battery takes over. When the external battery drops below the "P" preset voltage (Between 10 volts and 3 volts depending on your requirements) the power is cut off to either prevent damage to the external battery or to run your equipment as long as possible. Detailed Specifications PST-DC-UPS-1212 Max Charge Current 400 milliamps Maximum pass-through current 3-5 amps depending on duration Also comes in a 10 amp version, click here Maximum pass-through wattage 36-60 watts depending on duration Type of battery charged Lead acid, VRLA, SLA, etc. Nominal Battery Voltage 12 Volts Battery Capacity 1 to 17+ Amp-Hours Size of module 72 mm x 49 mm x 9.5 mm 2.80inches x 1.92 inches x 0.37 inches External battery connects when the input voltage to the module drops below 13.1 to 11.9 volts, see suffixes below External battery is disconnected from the load when the external battery's voltage drops below 10 to 8 volts, see suffixes below Temperature Minimum ambient temperature -10°C (-40°C available upon request) Maximum ambient temperature of 70°C Connection 6 Faston spade terminals, clearly labeled 3 Ground terminals External battery positive Load positive Car positive Weight 1.9 ounces, 54 grams Ordering See the shopping cart below The PST-DC-UPS-1212 can be ordered with a range of "N" and "P" values, as explained in the following table. Suffixes* Voltage at which car battery is cut of from the load Voltage at which auxiliary battery is cut off from the load Why? N13.1 (most common choice) 13.1 ±0.2 volts   Load is disconnected from the car electrical bus when the ignition is switched off N12.9 12.9 ±0.2 volts     N12.8 12.8 ±0.2 volts     N 12.7 12.7 ±0.2 volts     N12.6 12.6 ±0.2 volts     N12.0 12.0 ±0.2 volts     N11.9 11.8 ±0.1 volts   Allows the load to be powered by the car battery most of the time but still start the car (barely). N?? Tell us what you need, the range is between 13.1 volts and 11.9 volts. The tolerance is ±0.2 volts     P10 (most common choice)   10 volts When deep cycling of the auxiliary battery is desired. P8   7-8 volts When longest possible system operation is desired regardless of loss of auxiliary battery cycle life. P??   Tell us what you need, the range is between 10 volts and 7 volts   **(For example PST-DC-UPS-1212-N13.1-P10 would be a module which disconnects from the car battery when the car voltage falls lower than 13.1 volts and turns the auxiliary battery off when it falls to 10 volts) Model Please allow up to 7 days for small orders, 30 days for large orders. Price for quantity 1-49 Price for quantity 50-99 Quantity 100-499 Quantity 500-1999 PST-DC-UPS-1212-N13.1-P10 also know as PC-DC-UPS. . . $50.00 OUT OF STOCK UNTIL MID JUNE $35 $29.50 $19.60 PST-DC-UPS-1212-N11.8-P10 also known as PC-DC-UPS. . . $50.00 OUT OF STOCK UNTIL MID JUNE $35 $29.50 $19.60 PST-DC-UPS-1212-Nxx-Pyy (xx is your choice between 11.9 and 13.1 volts yy is your choice between 10 and 8 volts) $50.00 OUT OF STOCK UNTIL MID JUNE $35 $29.50 $19.60 DIN Rail mounting kit (see below) $6.00 $4.20 $3.80 $2.95 In-line fuse kit, consists of 3 in-line automotive spade fuse holders for the car+, battery+ and load+ lines. Includes 10 amp fuses. In-line fuse kit, consists of 3 in-line automotive spade fuse holders for the car+, battery+ and load+ lines. Includes 10 amp fuses. $22.00 $18.30 $15.90 $14.25 Hook up diagram: Connection diagram Dimensions, click on drawing for larger view DIN rail mounting option Questions and Answers 1. Q: My application needs more pass-through current, what can I do? A: We have a new module with power up to 120 watts. Click here for details. 2. Q: When the module turns off because both batteries are below their set points when does the module turn back on. A: The module turns back on only when the car's voltage is restored to the proper charge voltage. A new auxiliary battery won't turn the module back on. 3. Q: What do you have for 24 volt systems? A: Use the 24 volt version of the 10 Amp backup module which will use 24 volt auxiliary batteries in a 24 volt vehicle. 4. Q: I need a signal to tell me what the status of the UPS, whether it is on the main circuit, the auxiliary battery, or turned off. A: Consider using the PST-DC-UPS-1212-5A, which signals the UPS status by sourcing 300 mA at 12V to run LEDs, relays, etc. 5. Q: I am charging a very small battery with this, the 400 mA charge rate is too high according to the battery manufacturer. A. The charge algorithm used is kind to the batteries even when the maximum charge rate is over the C/3 rate specified by the battery manufacturers. For more information click on this link. To order, please call 801-764-9060, 9062, 9063, or 9064, FAX to 801-764-9061, or use our shopping cart. You can cancel your order any time before you submit your payment. Wholesale, manufacturer's and OEM pricing available. Custom modifications at low cost.

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