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MSV10: "sbreak"

This may or may not be indicative of a further problem/bug.

I found a part in the "Basic" group called "SBREAK."  I didn't know what it was, so I dropped it into my schematic.   Then I double-clicked it to check the info.  The info I got was for a "Voltage-Controlled Switch, but that's not what this thing is.

1.  What is SBREAK and how do one use one?

2.  There may be other parts with the wrong info.  For example, "Voltage-Controlled Switch" gives one plain Jane switch info.  Hence, you may have an offset that is out of sync somewhere.


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SBREAK is a voltage controlled switch, but instead of a "connected-unconnected" behaviour, you can define the resistance the switch provides between pins 1&2 based on the voltage between pins 3&4. There is a constant 1GOhm resistance between pins 3&4. You can see this if you place the component, then export the netlist (Transfer > Export Netlist)

When the voltage is less than VON, the resistance is RON. When the voltage is greater then VOFF, the resistance if ROFF. When the voltage is between VON and VOFF, the resistance is an exponential function of the input.

Many of the SMPS sample files (transient only) use the SBREAK component. For example, the sample file SMPS Circuits\Transient Analysis\Full VM.ms10

When I place the component, view the properties, then click Info, I see the help topic that is specific to SBREAK. I'm not sure where you are seeing other parts with incorrect info.
Garret
Senior Software Developer
National Instruments
Circuit Design Community and Blog

If someone helped you, let them know. Mark as solved or give a kudo. 🙂
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SBREAK

This device is a voltage-controlled switch.

To change the component’s parameters:

  1. Double-click on the placed component and select the Value tab.
  2. Change the following as desired:
    • On-state Voltage (VON) — voltage at which the switch turns on.
    • Off-state Voltage (VOFF) — voltage at which the switch turns off.
    • On-state Resistance (RON) — resistance of the device during its on-state.
    • Off-state Resistance (ROF) — resistance of the device during its off-state.
  3. Click OK to save to close the dialog box.

The above is the info for "SBREAK."

Below is the info for Voltage-Controlled Switch."

Switch

Switches are interactive components that can be closed or opened (turned on or off) by pressing a key on the keyboard, or by using the mouse.

To specify the key that controls the switch:

  1. Double-click on the switch and select its Value tab.
  2. Select the key in the Key for Switch drop-down list and click OK.

To toggle the switch on or off using the keyboard, press the identified key.

To toggle the switch on or off using the mouse, hover the cursor over the switch’s arm and click when the arm takes on a thickened appearance.

Non-interactive Switches

A small number of switches, for example, time delayed switches, current controlled switches and voltage controlled switches are not interactive components. For these components, the contents of the Value tab will be different than those described above, and will vary depending on the selected component.

Change the settings for these devices in the usual manner; double-click on the component, select the Value tab, and enter the desired parameters.


---- continuing ----

Thanks for the help.  Although, I'm still curious about how I'd use such a thing.  Ron, Ae(bR), Roff???   Is there such a thing in reality, or is this SBREAK just a construct for modeling?  I've never heard of the thing.

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My understanding is that SBREAK is just a construct for modelling, just as the vswitch within the component is a construct for modelling. It allows changing circuit connections during simulation, and is often found in the model of Opamps, along with other uses. The non-ideal behaviour is a continous curve, which is important for convergence when the switch opens/closes.

You can also have a look at v_switch, which is new to 10.0.1. It uses the same syntax as vswitch (except for the underscore), but has improved convergence properties. The primary difference is the curve is "smoother."
Garret
Senior Software Developer
National Instruments
Circuit Design Community and Blog

If someone helped you, let them know. Mark as solved or give a kudo. 🙂
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