Turn-signal indicators—also known as blinkers or flashers—are perhaps one of the most critical safety features on automobiles today. Automotive flashers are used in turn signals as well as a hazard or warning flashers. They help to communicate the intentions or actions of one driver to other drivers and pedestrians around them. The most common form of turn-signal indicator used in earlier model automotive applications is the thermal flasher, where later models often use solid state flashers.
What Is a Thermal Flasher?
A small round cylinder found in the fuse box of an automobile, the thermal flasher is an inexpensive part and is constructed in the following way:
- An electrical contact allows the flow of electrical current into the flasher
- This contact attaches to a curved piece of spring steel
- Resistive wire wraps around another piece of spring steel
How It Works
Though it happens instantly, an elaborate process takes place inside of a thermal flasher. Activation of the thermal flasher takes place using the turn-signal bar or the hazard lights switch. Initiating the process leads to a series of reactions.
- Pushing down or raising up the turn-signal bar on the car completes the circuit, sending current flow through the flasher to the bulbs in the turn-signal lights. Initially, the current flows only through the resistive wire and on to the signal bulbs without contact with the spring steel and contact. The current flow is so minimal that it is not enough to create a dim glow in the bulb.
- The resistance to the current causes the spring steel to heat up, expand and make contact, which provides the necessary flow to light up the turn-signal bulb.
- The spring steel cools off quickly, interrupting the current flow, and causing the turn-signal bulb to stop glowing.
- Rapid heating and cooling taking place within the thermal flasher cause the turn-signal bulb to flash one or two times per second. The sound associated with the turn-signal is caused by the spring steel touching the contact as it expands and completes the circuit.
What Is a Solid-State Flasher?
Late-model cars make use of more digital technology, adding solid-state flashers to the range of electronic components activated by computer chips. When activation of the turn signal or hazard lights takes place in a car with a solid-state flasher, the current produced flows through a timing chip.
Current flow through the timing chip causes it to activate, interrupt, and reinitiate current flow to the turn-signal bulbs using a transistor. This action mimics the blinking produced by a thermal flasher. In addition to mimicking the flashing operation, solid-state flashers also mimic the clicking sound produced by a thermal flasher in order to provide an audible signal to the driver.
Flashers from Amperite
Amperite carries all types of replacement flashers for early and late-model vehicles. Our knowledge and experience of flashers, sequential relays, and other related components ensure we will help customers find the right flasher type for their application.
Contact us and allow the Amperite team to help you choose the right thermal or solid-state flasher to fit your vehicle.