Pololu Pushbutton Power Switch LV
The Pololu Pushbutton Power Switch is a patent-pending design initially created for our Orangutan Robot Controllers as an alternative to bulky mechanical switches. The switch is intended to be the main power switch for a DC device requiring up to several amps of current. Please see the detailed description for product details and limitations. This item is the 2.5-7.0 V low-voltage version.
The Pololu Pushbutton Power Switch is a compact, solid-state power switch controlled by a momentary pushbutton switch. Because the switched current does not flow through the mechanical switch, a large variety of small, low-power switches can be used to control a substantial amount of power. The use of momentary pushbutton switches also allows multiple switches to be used in parallel to control the power to one load. The solid-state switch also allows the load to turn off its own power, which can be beneficial when used with battery chemistries sensitive to over-discharging. Please note that this switch has several drawbacks when compared to mechanical switches, so please be sure you fully understand this product before using it in your system.
Benefits and Limitations
The Pololu Pushbutton Power Switch works well in its intended application as a DC power switch for small robots, but because it is fundamentally different from a mechanical power switch, the benefits and drawbacks of the components must be fully considered.
Benefits over mechanical switches:
- Compact size
- Allows multiple (parallel) switches for improved user interface
- Better turn-on characteristics than a bouncing mechanical switch
- Limited LC spikes for low-resistance loads
- Allows self-shutoff
- Breadboard and perfboard compatible
- Drawbacks compared to mechanical switches:
- Switch is one-directional (inherent body diode in MOSFET)
- Limited operating voltage range
- Switches DC only (does not maintain state through power disruptions or excessive noise)
- No complete isolation in off state
- Dimensions: 0.4" x 0.9" x 0.125" (without header pins and pushbutton installed)
- Operating voltage: 4.5-20 V (SV version), 2.5-7.0 V (LV version)
- Maximum current: 10 A (see MOSFET datasheets)
- Weight without included pushbutton: 0.030 oz (0.85 g)
- Weight with included pushbutton: 0.035 oz (1.0 g)
- Draws very little current in off state (typically under 0.01 uA)