There are three pairs of external connection terminals on the MISO unit. They are labeled MAIN, SECONDARY, and OUTPUT. Each pair of terminals has a red and a black binding post connector. The MAIN pair of terminals is the connection for the primary power source that will power the OUTPUT. The SECONDARY pair of terminals is the connection for the back-up or reserve power source that will power the OUTPUT. The OUTPUT terminals are where the external circuit is connected to the MISO to receive power from one of the sources, either the MAIN or SECONDARY source. Located below the OUTPUT terminals is an indicator light that tells if a voltage is operating at the OUTPUT. The brightness of this light increases as the voltage at the OUTPUT increases and gets dimmer as the OUTPUT voltage decreases. You will learn to know the condition of your OUTPUT voltage from the brightness of the indicator light.
1. CONNECT THE MAIN SOURCE
Connect the positive lead from the main source to the red terminal of the MAIN input of the MISO. Connect the negative lead from the main source to the black terminal of the MAIN input.
2. CONNECT THE SECOND SOURCE
Connect the positive lead from the secondary source to the red terminal of the SECOND input of the MISO. Connect the negative lead from the secondary source to the black terminal of the SECOND input.
3. CONNECT THE EXTERNAL CIRCUIT
Connect the positive lead from the external circuit to the red terminal of the OUTPUT of the MISO. Connect the negative lead from the external circuit to the black terminal of the OUTPUT.
You have now connected the MISO unit and it is ready for operation.
The MISO 13.5-12 is designed to have the voltage on the MAIN terminal, generally higher than the voltage connected to the SECONDARY terminal. There are two ways to connect sources to the terminals. The source leads can be connected to the binding posts or they can be inserted into the banana sockets. To be inserted into the banana sockets the leads must have banana plugs on their ends. In general most leads coming from sources that have wire ends or spade lug ends can be connected to the binding posts.
To use the binding post connector screw the thumb nut up to allow enough space for the lead to be connected to the terminal. Put the lead around the binding post, being careful to enable the lead to make good electrical contact with the post and base when the thumb nut is screwed down. Keeping the lead in place, screw the thumb nut down unto the lead to capture it. Tighten it enough to prevent the lead from pulling out of the terminal easily.
To use the banana plug connectors insert the banana plug on the end of the lead into the hole in the center of the binding post. It is not necessary to remove, loosen, or tighten the thumb nut. The banana plug should fit tightly into the socket by its own friction. If it does not, increase the flare in the middle of the plug with a screwdriver until the plug fits tightly in the banana socket.
The sources that can be connected to the MISO unit are voltage sources that have two leads. One of the leads is a positive lead and the other is a negative lead.
The source with the highest voltage is connected to the MAIN terminals and the lower voltage source is connected to the SECOND terminals.
Using the leads of the source that is going to be the main source connect the positive lead to the red binding post of the pair of terminals labeled MAIN on the MISO. Connect the negative lead of this source to the black binding post of the MAIN terminals.
Using the leads of the source that is going to be the back-up power source connect the positive lead to the red binding post of the terminal labeled SECOND on the MISO. Connect the negative lead of this source to the black binding post of the SECOND terminals.
The loads that will receive power from the MISO unit are connected at the OUTPUT terminals of the unit. Connect a lead from the load for the positive potential to the red binding post at the pair of terminals labeled OUTPUT on the MISO. Connect the lead from the load for the negative or ground potential to the black binding post of the OUTPUT terminals.
The MISO unit performs a source switching function for a load that is connected to the OUTPUT terminals of the device. The switching occurs between the source at the MAIN terminals and the source at the SECOND terminals as follows.
The MISO 13.5-12 is designed to operate with a 12V supply at the MAIN terminal and a 3-cell lithium ion battery at the SECOND input. When the source at the MAIN terminals is turned on it has a magnitude of 13.5V. The source at the SECOND terminals has a voltage of 10.8V, a few volts less than 12V. When the MAIN voltage starts to fall it continues to supply the load until it falls below 12V. At this point, the source is switched and the SECOND source is connected to supply the load. The SECOND source supplies the load until the MAIN source climbs to its turn on voltage. But the MAIN source must climb all the way to 13.5V before the source is switched and the MAIN is allowed to supply power to the load again. The model number then describes the source switching voltages of the MISO unit. The MISO 13.5-12 switches the MAIN off at 12V and back on at 13.5V. When the MAIN source is off the SECOND source is on.
In general, the SECOND source is always on but one property of the MISO circuit is that the highest voltage is placed on the output and the other is blocked when both inputs are turned on. So the conditions where the voltage on the SECOND input varies from its design value does not change the switch points of the MISO unit, that is 13.5V on and 12V off, but this may change which source appears at the OUTPUT when the SECOND source voltage equals or exceeds the MAIN source voltage.
The MISO 13.5-12 may be operated with only one voltage source connected to it. This is accomplished by connecting that source to the SECOND input and leaving the MAIN input open or unused. In this case the SECOND input may have a recommended voltage between 5V and 15V connected to it. The voltage that is connected to the SECOND input will appear at the OUTPUT terminals of the MISO. There will be no source switching occurring in this configuration. The SECOND source will be constantly connected to the OUTPUT.
Single-sided operation using the MAIN input is possible but is not recommended unless the source always stays above 12V or the on/off switching with no back-up source is actually wanted.
Inputs: 2 sets of binding posts with banana plug terminals with 1 red and 1 black terminal in each set
Binding Post Terminals Dimensions: 5/32" (4 mm) ID, 7/32" (5.5 mm) OD, 5/16" (8 mm) height
Max Voltage Input: 20 V DC, 15 V DC recommended
MAIN Input Switch Voltage Levels: 13.5 V on, 12 V off
Max Current Input: 15 A DC, 12 A DC recommended
Output: 1 set of binding posts with banana plug terminals with 1 red and 1 black terminal
Internal Circuit: Power Integrating Module with Pulsed Driver. Single ground point. All black terminals are connected to the single ground.
LED indicator light: Brightness proportional to OUTPUT voltage
Form Factor: Cylinder from the standard 3 in. PVC system.
Dimensions: 3 in. (76.2 mm) ID, 3.5 in. (88.9 mm) OD, Length ~ 6in. (152 mm)
Material: Foam core Polyvinylchloride (PVC)
Weight: 7.3 oz. (206.95 g)
Caps: Two Polyethylene 3.5 in. diameter
MISO UNIT TOTAL WEIGHT: 12.5 oz. (354.4 g)
Some effort has been made to make the MISO water resistant during its construction at the manufacturing plant. If it is to be used outdoors in an environment where it will be exposed to a lot of moisture or high humidity, it is recommended that measures be taken to make it watertight. To do this use a water resistant sealant around the edges of the binding post terminals. Fill in the gaps around these connectors. Also seal the area around the LED lens and the edges of the caps.
To prevent rusting of the binding posts the MISO unit can be sealed in a plastic bag or some other container that will not let the water in. Seal around the area where the leads from the MISO go through the bag or container to the sources and position this fixture so that water drains down the lead wires away from the MISO terminals.
The pulse driver circuit is used to drive the INDICATOR LIGHT LED in the MISO unit. It can be accessed by removing the bottom enclosure cap (the cap below the LED light). The LED light is connected to a two port screw terminal that is visible when looking into the MISO. This two port terminal is the output of the Pulsed Driver. This two port terminal can be used to drive other circuits. See the data sheet for the Power Integrating Module with Pulsed Driver to determine if and how you can use this circuit for your purpose.
© 2009 Plane Space Design
MISO is a product brand name created by Plane Space Design.