04-17-2014, 08:22 PM | #1 |
Not Yet Wild Location: Houston area | 48v to 12v converter - what to do with the 12v negative wire? Hi Experts, I need your help please. I am trying to add a 12 volt converter to my golf cart and don't know what to do with the 12v negative wire - let me explain. The converter is a SUPERNIGHT - I have a 2004 'Electric I.Q. Golf Car, 48 Volt Regen' per the serial number sticky - thanks! It has six 8 volt batteries. I see the 48 volt positive and negative wires going to the batteries. I know I need to connect the positive and negative 48v wires of the converter to these respectively - I am ok with connecting this side of the converter. I see a yellow wire coming off the + side of the 2nd battery from the negative 48 volt side of the cart. I know I need to remove this from the battery, and connect this to the positive 12v lead from the converter. I am ok with this. What do I do with the negative 12v lead from the converter? Should I put it on the negative 48 volt side of the cart too? That would mean I am joining the negative wires of the converter together - is that ok? Thank you! Keith. |
The post explains a voltage high current doubler circuit which will almost double the voltage that's been applied at the input (up to 15V max), and also it becomes specifically useful since it allows higher current loads to be used at the output, in the order 10 amps.
Since the voltage doubler circuit explained here is able to handle high current loads, the design becomes ideally applicable for raising solar panel voltages when there's no adequate amount of sun light incident on the panels.
Circuit Operation
Looking at the given circuit diagram, let's assume we apply a 12V at the input of the circuit, the output would generate a potential of around 22V.
The circuit initiates its functioning when IC1a, R2 and C2 starts generating rectangular waves.
Reliance 36V/48V-12V Voltage Reducer/Converter (Universal Fit) DC voltage reducer/converter to reduce your 48-volt or 36-volt electric cart to 12 volts to run all of your accessories. Connects to entire battery pack instead of just one battery, which improves the life of the batteries.Specifications:Works with 48-vol. High Current Voltage Doubler Circuit. Looking at the given circuit diagram, let's assume we apply a 12V at the input of the circuit, the output would generate a potential of around 22V. Use a 12 to 18 volt 'charge pump' converter that would eliminate the need for the extra batteries and complex switching circuitry. Multiple circuits in.
This signal also reaches at the output of IC1d, albeit in an inverted mode.
The presence of R2, C2 delays the output of IC1a which causes the output of IC1b to attain less than 0.5 duty factor, resulting in a waveform where the negative half may be shorter than the positive half).
The above also becomes true at the output of IC1c, were the input data is delayed with the help of C7, R5.
The output from IC1c which is in an inverted form is further buffered thrice via IC3f, IC3a and the gates in parallel IC3b-----IC3c.
The output from the above is finally used for driving the power mosfets.
The transistor T1 is driven from the output of IC1b..... when T1 is ON, the point between R6, R7 attains a 2V potential, however since IC2a requires a 11 to 22V input, the negative potential for this chip is plucked from the positive of the input voltage, because the supply voltage and the collector of T1 is already subjected with the doubled voltage.
D1 is introduced to guarantee that the input to IC2a never drops below 10.5 V.
During the conduction periods of T1, T2 and T3 conduct alternately.
When T2 is switched ON, C10 gets charged with voltage equal to the input supply voltage through T3 and D3.
When T2 is turned OFF, and T3 gets ON, C9 goes through identical process as C10 above. However C10 holds the charge due to the presence of D3 which stops it from discharging.
Because the two capacitors are in series, the net voltage now attains a level that's almost twice that of the applied input voltage.
One interesting thing here is, since the circuit involves many inverting stages and also a few delay networks, the output mosfets can NEVER conduct together which makes the circuit extremely safe with the operations.
C1 buffers the input applied voltage in order to load the input with constant power irrespective of the varying current parameters across the output.
The components which are marked with dashed circles need to be appropriately cooled by adding large heatsinks to them.