Johnson Screwdriver Tester 4.5 × 100 mm

The Johnson Screwdriver Tester 4.5 × 100 mm is a combination electrical voltage tester and flat-head screwdriver designed to detect the presence of AC voltage while also functioning as a standard screwdriver for tightening and loosening screws. It is commonly used by electricians, technicians, engineers, maintenance personnel, and DIY users for testing live electrical circuits and performing basic electrical installation and repair work.

The tester is manufactured with a transparent insulated handle, a 4.5 mm flat (slotted) hardened steel blade, a 100 mm shaft length, a high-value resistor, a neon indicator lamp, a metal contact cap, and a protective insulated body. The transparent handle allows the user to easily observe the neon lamp when voltage is detected.

The working principle of the Johnson Screwdriver Tester is based on neon lamp voltage detection. When the metal tip touches a live AC conductor and the user places a finger on the metal contact cap at the end of the handle, a very small current flows through the internal high-value resistor and neon lamp. If voltage is present, the neon lamp glows, indicating that the conductor is live. The internal resistor limits the current to a safe level during normal operation.

Typical specifications include:

• Product Type: Screwdriver Voltage Tester

• Brand: Johnson

• Model Size: 4.5 × 100 mm

• Tip Type: Flat (Slotted)

• Blade Width: 4.5 mm

• Blade Length: 100 mm

• Blade Material: Hardened Chrome Vanadium Steel

• Handle Material: Transparent Insulated Plastic

• Voltage Indicator: Neon Lamp

• Detection Type: Contact AC Voltage Detection

• Operating Voltage: Typically 100–500V AC (may vary by model)

• Power Source: No Battery Required

The Johnson Screwdriver Tester 4.5 × 100 mm can be used for:

• Detecting live AC wires

• Checking electrical sockets

• Testing switches

• Inspecting power outlets

• Testing extension boards

• Identifying phase wires

• Electrical maintenance

• Tightening and loosening slotted screws

• Household electrical repairs

• Industrial electrical servicing

The applications of the Johnson Screwdriver Tester include electrical wiring installation, household maintenance, industrial electrical maintenance, appliance repair, electrical panel inspection, educational laboratories, engineering workshops, prototype development, automation systems, and DIY electrical projects.

The advantages of the tester include dual functionality as both a screwdriver and voltage tester, compact and lightweight design, transparent insulated handle for easy indicator visibility, durable hardened steel blade, no battery requirement, easy operation, portable design, reliable voltage detection, low maintenance, and long service life.

Safety Precautions

• Use the tester only for AC voltage detection within the specified voltage range.

• Hold the tester only by the insulated handle.

• Touch the metal contact cap with your finger during voltage testing.

• Never touch the metal blade while testing a live circuit.

• Do not use the tester if the handle is cracked or damaged.

• Test the screwdriver on a known live circuit before use to verify proper operation.

• Do not use it as a replacement for a digital multimeter when accurate voltage measurement is required.

• Wear appropriate personal protective equipment (PPE) when working on electrical systems.