EL3041S(TA) Optotriac Zero-Cross Driver for AC Switching

ElecSuppliers Part Number GuideAug 22, 2026

EL3041S(TA) is an optotriac from Everlight Electronics designed for isolated AC switching and power control applications. It combines an infrared LED input with a TRIAC output and uses zero-voltage crossing technology to help control AC loads with reduced switching transients.

The device is part of the Everlight EL304X optotriac family and is designed for applications where electrical isolation is required between a low-voltage control circuit and an AC power circuit.

EL3041S(TA) Key Features

EL3041S(TA) provides 5 kVrms insulation voltage between the input and output sides. The output is designed as a zero-voltage-crossing TRIAC driver, allowing the device to switch the AC output when the voltage is close to the zero crossing point.

The device has a trigger current of 15 mA and an off-state output voltage rating of 400 V. It is supplied in a surface-mount package with a gull-wing lead configuration.

The zero-crossing function is particularly useful in AC switching circuits because switching close to the AC zero crossing can reduce sudden voltage changes and electromagnetic interference compared with random-phase switching.

How EL3041S(TA) Works

EL3041S(TA) provides optical isolation between the control side and the AC load side.

When an appropriate current is applied to the input LED, the optical signal activates the TRIAC output circuit. Because the device uses zero-voltage crossing operation, the output does not simply turn on at an arbitrary point of the AC waveform. Instead, the switching action is synchronized with the AC waveform.

This makes the device suitable for applications where controlled AC switching is more important than precise phase-angle control.

The optical isolation also means that a low-voltage controller does not need a direct electrical connection to the AC switching circuit. This can help separate the control electronics from potentially hazardous or electrically noisy power circuitry.

EL3041S(TA) Applications

EL3041S(TA) can be used in AC load switching, solid-state relay circuits, heater control, appliance control, industrial control equipment and other systems where a low-voltage control signal needs to operate an AC load.

The zero-crossing characteristic makes the device particularly suitable for resistive loads such as heaters and lamps where full-cycle or zero-cross AC switching is appropriate.

It can also be used as the optically isolated driver stage for an external power TRIAC. In this type of circuit, EL3041S(TA) handles the isolated triggering function while the external TRIAC provides the required load current and voltage capability.

EL3041S(TA) and Zero-Cross Switching

Zero-cross switching is one of the main reasons to select EL3041S(TA) instead of a random-phase optotriac.

When an AC waveform approaches zero voltage, the voltage difference across the switching device is relatively low. Triggering the output around this point can reduce the abrupt electrical transition associated with switching at a higher point on the waveform.

For equipment containing motors, heaters, lamps or other AC loads, the appropriate switching method depends on the load characteristics. EL3041S(TA) is intended for zero-cross applications rather than applications requiring arbitrary phase-angle triggering.

EL3041S(TA) Package and Electrical Design

EL3041S(TA) is designed for surface-mount PCB assembly. Current distributor information identifies it as a single-channel optotriac in a six-pin gull-wing SMD configuration. The device has a 5 kV insulation rating and a 15 mA trigger-current specification.

The maximum output off-state voltage is listed as 400 V. Designers should not treat this rating as the recommended operating voltage for every AC system. The actual circuit design must account for the AC supply, transient voltage, load characteristics and any additional protection components.

When using EL3041S(TA) to drive an external power TRIAC, the gate-current requirements of the selected TRIAC should be checked against the optotriac output characteristics.

EL3041S(TA) Replacement Considerations

When replacing EL3041S(TA), engineers should check more than the basic optocoupler function.

The replacement should have compatible zero-cross behavior, insulation voltage, output voltage rating, trigger current and package configuration. A random-phase optotriac may have similar pin functions but may not behave correctly in a circuit designed around zero-cross switching.

The suffix should also be checked carefully. Everlight offers multiple versions within the EL304X family, including different package and electrical configurations. Public manufacturer documentation lists EL3041S(TA), EL3041S1(TA) and related variants as separate ordering part numbers.

EL3041S(TA) Availability

Current distributor information shows that EL3041S(TA) can still be sourced through electronics distribution channels. For example, TME currently lists the exact part number and shows available inventory, while another distributor describes it as available while stock lasts.

This difference in distributor status is important when sourcing the part for production. Availability can vary between regions and distributors, so buyers should confirm the exact package, manufacturer part number and current inventory before placing an order.

EL3041S(TA) for AC Power Control

EL3041S(TA) is a practical optotriac solution for isolated zero-cross AC switching. Its combination of 5 kVrms isolation, 400 V output capability and 15 mA trigger current makes it suitable for many low-power AC control interfaces.

For new designs, the complete AC switching circuit should be evaluated as a system. The external power TRIAC, load current, mains voltage, surge protection, PCB creepage and clearance, thermal conditions and isolation requirements all need to be considered together.

For replacement and maintenance applications, the exact EL3041S(TA) ordering code is equally important because closely related optotriac variants can have different electrical or mechanical characteristics.