Choosing the Right Electronic Switch
1. How do I choose the right electronic switch?
Start with seven variables: switch type, rated voltage and current, contact configuration, actuation method, mounting style, operating environment, and required certifications. For power switching, check AC/DC load and inrush current first; for signal switching, check contact resistance, plating, operating force, and life expectancy. Salecom can recommend toggle, rocker, pushbutton, tact, slide, DIP, or micro switches based on your application.
2. What's the difference between toggle, rocker, pushbutton, and tact switches?
Toggle switches suit clear ON/OFF or multi-position switching and are common on industrial and power control panels. Rocker switches suit panel-mounted power control and can be illuminated. Pushbutton switches support momentary or latching operation for equipment controls and automotive panels. Tact switches are used for low-current PCB signal input and are common in automotive interiors, medical devices, and consumer electronics.
3. What do momentary and latching mean?
Momentary action closes the circuit while pressed and returns to its resting position when released — used for start, reset, or signal input. Latching action holds its state after one press and resets on the next — used for power switching or mode changes. If a safety function requires a guaranteed reset, that needs to be verified at the circuit and mechanism level, not assumed from the switch alone.
4. How do I read NO, NC, SPST, SPDT, and DPDT?
NO (normally open) doesn't conduct until pressed; NC (normally closed) conducts until pressed. SPST (single-pole, single-throw) is a simple ON/OFF; SPDT (single-pole, double-throw) switches between two circuits; DPDT (double-pole, double-throw) controls two circuits simultaneously. Select based on actual circuit function, not visual similarity to another part.
5. What changes when selecting for low-current signal switching versus high-current power switching?
Low-current signal switches are chosen for stable contact behavior, low contact resistance, gold or silver plating, and spring feel. High-current power switches are chosen for rated current and voltage, inrush current tolerance, flame-retardant materials, and safety certifications. The two categories are not interchangeable by appearance alone — always confirm electrical load and life requirements match.