6 – 12 Volt Converter

PROBLEM Many vintage and classic cars are still either: The original 6 volt electrical system, and often positive chassis The original 12 volt electrical system, but still positive chassis Many vintage and classic car owners: Do not want to convert or otherwise change the vehicle’s original characteristics Would like to fit an Air Conditioning system Would like to be able to operate modern accessories in the vehicle, particularly when on a trip or rally FACTS All modern in-car Radios, CD players, and DVD players are designed to operate from a 12 volt DC supply. They also require a negative chassis vehicle. It is almost impossible to safely isolate a modern radio in a positive chassis vehicle. All GPS navigation units, Cell-phone chargers, Digital Camera chargers, almost every type of accessory require 12v. Modern A/C electric clutches are commonly 12v, not 6v. SOLUTION A specialised form of voltage regulator or Converter, known as a boost type, can be used to allow the safe operation of the above devices. The Cruising Electronics CE412V (was SR6138V) Converter is actually a Buck – Boost type. That means it has two modes of operation: Buck mode: If the input voltage is above the fixed output voltage, the Converter will drop (buck) it down. Boost mode: If the input voltage is lower than the fixed output voltage, the Converter will boost (increase) it. For 6v car use, we only need to concern ourselves with the boost mode, whereby 6v is boosted to 12v (Buck mode would come into play if for example we were wanting to operate the 12v accessories in a 24v truck)

Not all boost regulators are the same:

1/ In order to be able to operate on positive OR negative chassis vehicles, without modification to the car or radio, the Converter must have complete electrical isolation between the input and the output terminals. Additionally, its metal case needs to be completely isolated from all the electrical terminals.

2/ The Converter should ideally operate at less than 6 volts input. Why? Older generators usually don’t have any charging output at engine idle. Therefore at idle, with the ignition system draw, and if any accessories such as lights are on, the vehicle battery voltage will drop below the nominal 6v.

3/ The Converter must be able to supply adequate output current for the devices it is intended to operate.

Model CE412V can easily supply 7 amps at 12.4v output, from a 6.0v input, perfectly adequate for a 50W peak per channel stereo at normal volume, and will simultaneously run your GPS and ‘phone charger. At just 4v input it will still supply 12.4 volts at 4 amps. See the CE412V brochure for further info. 12 volt A/C magnetic clutches typically require about 3.5 amps to pull in. An O/D solenoid has not been tested, but if it requires less than 5 amps should be ok.

The CE412V should not be used for motor driven devices, for example electric windows or wipers, without first consulting Cruising Electronics.

• Input voltage from 4.0 to 36 volts, (so can also be used on 12v + chassis, or 24 volt system of + or – chassis)
• Works on Positive OR Negative chassis vehicles – no modifications necessary to the vehicle or the Converter
• Output voltage fixed at 12.4 volts DC ± 2%
• Output current 2 amps @ 4.0 volts input
• Output current 5 amps @ 5.5 volts input
• Output current 7 amps @ 6.3 volts input or higher
• Fan cooling built-in – automatic temperature controlled
• Standby current (no output load) 200mA @ 6.5v
• Conversion efficiency varies with voltage and load, 82% at 5v input
• Polarity reversal protection
• Output voltage ripple factor < 1%
• Input/Output isolation between input and output leads and the leads and frame is 500 volts
• Weight 685 Grams (1.5 lb)
• Dimensions 150 x 55 x 95 mm (6” x 2.1” x 3.75”)
• Ambient temperature allowable from -20 to +80 degrees C (-4 to +176 F)
• Input and output connections by colour coded bare wire leads, with a fuse incorporated in the input + lead
• All specifications subject to change or design improvements without notice