APPLICATION NOTE 009

VOLTAGE AND CURRENT AMPLITUDE MANIPULATION

Benjamin Bacon, Owner, Plane Space Design

The information contained in this application note is based upon the the contents of Application Note 004 Daisy Chaining MISO Units. If you have not already done so, reading that document will make understanding this application easier.

It is possible to use a complex of MISO units to generate new amplitudes of voltages and currents from the voltages and currents that are available from sources. There are four basic ways to modify the amplitudes of the outputs from these sources.

  1. Connect the inputs of a MISO complex in series

  2. Connect the inputs of a MISO complex in parallel

  3. Connect the outputs of a MISO complex in series.

  4. Connect the outputs of a MISO complex in parallel.

CURRENT DIVISION & VOLTAGE AMPLIFICATION

If all  the the inputs of an N stage MISO complex are connected in parallel from a single source, the units have the same voltage at their OUTPUT terminals and share the current sourcing responsibilities equally. The portion of the total output current that comes from each input will be 1/2N of the total. This essentially effects current division.

After current division the current can be reintegrated at the outputs by connecting the OUTPUT terminals in parallel. Starting from the last stage, N, the current output can be tapped to get an increasingly larger current supply at each stage down to stage one. At stage one the total current is available from its OUTPUT. Each stage increases the output current by 1/N of the total possible current.

If after current division the outputs of each stage are connected in series, voltage amplification will occur. The OUTPUT terminals at stage one will carry N times the input voltage. The voltage chain that subsequently results can be tapped to obtain voltages between the input voltage and N times the input voltage in steps of Vin.

VOLTAGE ADDITION

Consider the connection of the 3-stage MISO complex above. The terminals on the other side of the MISO units are connected in the same way to the same voltages. The output terminals for each stage are located to the upper left of the stage, at the position where the OUT label is placed for stage A in the diagram. These outputs are the connection points at which the voltages can be accessed. There are three voltage outputs available from this connection configuration. Voltage A, voltage B, and voltage C = A + B. 

If the outputs are connected in series the available voltages will be  from right to left, A + B, B + (A + B),  and A + B + (A + B) = 2A + 2B. The outputs cannot be connected in parallel but there is a series-parallel connection available. Connect the A output in series to output B and then connect these in parallel to output C.

The benefits  of voltage and current amplification and division are the provision of an ability to accomplish more with the sources that one has available. Often the needed sources can be simulated with the right types of connection.

Example:

You have two renewable energy sources. Source A that converts solar radiation into energy and only works in the daytime. Source B that uses wind and works marginally in the daytime but really works well at night because of a dependable strong night breeze in your locale. You want a way to take advantage of the power of  the right sources at the right time.

The solution to this problem is already begun in the diagram above. You connect source A and B in series so that B adds its small daytime contribution to A. Connect A + B to the MAIN side of MISO C. This is the daytime source that will appear at the output of C. To finish the solution connect the output of stage B to the SECOND side of stage C. This is now your nighttime source, that will be switched to the output of C at night when the breezes blow and voltage and current of B is high. The solution comprises a day/night MISO complex.