B2J0101 Economical Power-up Delay Module

Name: B2J0101 Economical Power-up Delay Module
Brand: DAIDISIKE
SKU: b2j0101-economical-power-up-delay-module
Availability: InStock

Low-cost power-up delay relay module with a 2-30 second adjustable delay and no trigger input required.

▶ Watch it in action: B2J0101 Power-On Delay Relay Module Demo — Set the Delay with One Potentiometer (5-24V)

B2J0101 Economical Power-up Delay Module - 220V AC to 12V DC version with wiring notes

🔍 Click to enlarge · 1/7

Technical Specifications

Delay Method	Power-up delay (countdown starts the instant power is applied; no trigger input)
Delay Range	2 - 30 seconds, adjustable via on-board potentiometer (clockwise to increase, counter-clockwise to decrease)
Core IC	NE555
Output	Single relay, NO/NC (transistor output variant also available)
Supply Voltage	5/9/12/18/24V DC (normal operating range 4.8-5.2 / 8.5-11 / 11-14 / 16-20 / 20-28V respectively)
Supply Ripple	< 1Vp-p
Supply Current	< 50mA (typical 40mA when the relay is energized)
Output Stress (normal operating)	Relay type: DC 30V or AC 0-220V, 8A; Transistor type: DC 12-48V, 8A
Output Isolation Voltage (normal operating)	Relay type < 250V; Transistor type < 130V
Absolute Max Supply Voltage	DC 5.3 / 11.5 / 15 / 22 / 30V for the 5/9/12/18/24V versions respectively
Self-Recovering Fuse	DC 30V, 500mA
Absolute Max Output Stress	Relay type: AC 250V, 10A; Transistor type: DC 55V, 10A
Absolute Max Output Isolation Voltage (type test)	Relay type: DC 1000V, 60s; Transistor type: DC 250V, 60s
Relay Mechanical Life	> 100,000 operations (> 10,000 under heavy load)
Operating Temperature	-20 ~ 60°C
Storage Temperature	-40 ~ 85°C
ESD Immunity (IEC61000-4-2)	1kV all terminals: normal operation; 2kV: no permanent damage
EFT Immunity (IEC61000-4-4)	500V / 5kHz / 2min: normal operation (delay time may shift slightly); 1kV: no permanent damage
Surge Immunity (IEC61000-4-5)	1kV, power terminals to ground: no permanent damage (by design)
Creepage Distance / Clearance	Measured > 9.2mm creepage (> 6mm required) / > 2.2mm clearance (> 2mm required), pollution degree 3
PCB Dimensions	55 x 30mm (L x W), tolerance ±5%
Mounting Hole Spacing	49mm (top-bottom) x 24.5mm (left-right)
Terminal Pitch	5.08mm
Terminals & Controls	5 screw terminals + 1 adjustment potentiometer + 2 LED indicators

Overview

B2J0101 is a power-up delay relay module built for engineers and OEM integrators who need a device that automatically switches a load on after a fixed interval once power is first applied, with no external trigger signal, button press, or control-line wiring required. It can be supplied from 5V, 9V, 12V, 18V or 24V DC, is built around an NE555 timing core, and the countdown begins the instant power is applied.

The delay is adjustable from 2 to 30 seconds using an on-board potentiometer (clockwise increases the delay, counter-clockwise decreases it), giving field technicians and production-line staff a simple mechanical setting with no programming or host computer required. The single relay output brings out both normally-open (NO) and normally-closed (NC) contacts, rated up to 250V AC / 10A as an absolute maximum (8A at AC 0-220V or DC 30V under normal operating conditions), with a supply current below 50mA (typical 40mA when the relay is energized).

Key Facts — B2J0101 at a glance

B2J0101's power-up delay is adjustable from 2 to 30 seconds via an on-board potentiometer, with no external trigger input — the countdown starts the instant power is applied.
B2J0101 can be supplied from 5V, 9V, 12V, 18V or 24V DC, with a supply current below 50mA (typical 40mA when the relay is energized).
B2J0101's single relay output is rated up to 250V AC / 10A as an absolute maximum, with a normal operating output stress of AC 0-220V or DC 30V at 8A.
B2J0101's output isolation voltage is type-tested to DC 1000V / 60s (relay type), with continuous operating isolation below 250V.
B2J0101 is rated for -20 to 60°C operation and -40 to 85°C storage, with a relay mechanical life greater than 100,000 operations (>10,000 under heavy load).
B2J0101's PCB measures 55 x 30mm with mounting hole spacing of 49 x 24.5mm and a 5.08mm terminal pitch.

Features & Benefits

No trigger input to wire - the delay starts the moment power arrives

B2J0101 has five screw terminals and nothing else to connect: supply positive to terminal 4, supply negative to terminal 3, and the load loop through the NO (0) and COM (1) contacts. There is no trigger terminal, no signal cable to run back to a sensor or PLC, and no polarity or level convention to get wrong, so an installer can turn a bare board into a working delay circuit in a couple of minutes.

NE555 timing core with a screwdriver-set 2-30 s potentiometer

The delay is set by turning the on-board knob (terminal 5) - clockwise to increase, counter-clockwise to decrease - anywhere from 2 to 30 seconds. No programming, no software, no host controller and no DIP-switch table: production-line staff can dial in the timing on the bench, and the blue action indicator (6) plus green power indicator (7) let them confirm the setting by eye without a meter.

Change-over contact means one module covers delay-on and delay-off

Both NO and NC contacts are brought out. The NO contact (0-1) is open at power-up and closes when the delay expires, which delays a load on. The NC contact (2-1) is closed at power-up and opens when the delay expires, so the same board can instead run a load for 2-30 seconds after power-up and then cut it - a purge fan, a pre-charge resistor, a start-up bypass - without adding any parts.

Isolated relay output that switches real loads, not just logic

The single relay is rated AC 250 V / 10 A as an absolute maximum, with a normal operating output stress of AC 0-220 V or DC 30 V at 8 A, and an output isolation type-tested to DC 1000 V for 60 s. The load circuit is galvanically separated from the module's timing side, so the same 12 V board can switch a mains-fed heater (with the optional case fitted) or a 24 V DC valve. Without a case, keep the switched circuit to safe voltages of 0-36 V.

Runs off the rail the machine already has, at under 50 mA

5 V, 9 V, 12 V, 18 V and 24 V supply versions are available (default ordering configuration M31 is 12 V with relay output), each with a generous window - the 12 V version accepts DC 11-14 V, the 24 V version DC 20-28 V. Supply current is below 50 mA, typically 40 mA with the relay energized, so the module can hang off a spare auxiliary output or PLC supply instead of forcing a bigger power supply into the panel. Other voltages are available on request.

Protection built in for the abuse a field board actually sees

Reverse supply polarity, overcurrent (a self-recovering DC 30 V / 500 mA fuse that resets itself instead of needing a service call), electrostatic discharge, electrical fast transient and surge protection are all on board. Tested to IEC61000-6-1-2016 light-industry requirements: 1 kV ESD on all terminals with normal operation and 2 kV with no permanent damage; 500 V / 5 kHz / 2 min EFT with normal operation; 1 kV surge from power terminals to ground with no permanent damage.

Creepage slots milled to beat the safety requirement by 50 percent

The PCB carries creepage slots isolating the high-voltage relay side from the logic side. Measured creepage is above 9.2 mm against the 6 mm required by IEC60950 at pollution degree 3, and electrical clearance is above 2.2 mm against a 2 mm requirement - margin that matters on a board this small, where the easy route would have been to meet the minimum and stop. Certification documents are available on request.

Optional transistor output for silent, high-cycle and inductive loads

A transistor-output variant replaces the relay with an open-drain stage rated DC 12-48 V (8 A under normal operating conditions, 10 A absolute maximum) with a 10 A flyback diode fitted, so it drives inductive loads such as electromagnets and motors directly. It is silent and has no contacts to wear, which suits duty that would eat through the relay's 100,000-operation mechanical life (over 10,000 under heavy load).

Applications

Dash cam and vehicle electronics delayed power-up — Vehicle supply voltage swings sharply at the moment of ignition; B2J0101 delays power to a dash cam, navigation unit, or other 12V accessory for a set interval so it powers up only once the supply has settled.

Motor and pump soft-start buffering — Placed between the main supply and a motor or pump, B2J0101 delays the motor's power-on by a few seconds after the main supply energizes, staggering it from other large loads to reduce inrush current and avoid nuisance trips.

LED display and signage sequential power-up — After the main power supply is switched on, B2J0101 delays turn-on of the display or lighting section, avoiding the power-on surge that can shorten the life of driver electronics and LEDs.

Security camera and PTZ power-on protection — Once mains power is restored, B2J0101 delays power to a camera or PTZ unit, giving the supply and network connection time to stabilize before the device starts up, reducing abnormal restarts.

Heating and fan preheat sequencing — After the main unit powers up, B2J0101 can delay the start of a heating element or fan so upstream stages run first, giving a simple mechanical power-on sequence without added control logic.

Staggered load restart after a power outage — When mains returns, every load in a panel tries to start at once. Fitting one B2J0101 per load and setting each knob to a different point in the 2-30 second range brings the loads back one at a time, spreading the inrush instead of tripping the upstream breaker - with no timer relay, contactor logic, or PLC program involved.

Models & Ordering Information

B2J0101 Power-up Delay Module

B2J0101

B2J0101 is a single ordering code, corresponding to the default 12V DC relay-output configuration (M31 in the B2J01 series coding scheme). Other supply voltages (5/9/12/18/24V) and a transistor-output variant are available; contact us for voltage customization.

How to Select

Choose B2J0101 when the application only needs a delay that starts automatically at power-on, with no external trigger signal or button — it has the simplest wiring and lowest cost of the B2J01 delay family.
If the delay instead needs to be started by an external level signal or pushbutton (e.g. a sensor output or switch), with selectable high/low trigger polarity, choose B2J0201 (level-triggered delay) instead.
If the application needs multiple delay modes (delay-off, cyclic on/off, edge-triggered, self-latching), delay ranges in seconds/minutes/hours, higher timing precision, or voltage-threshold detection, choose B2J0601 (multi-mode delay) instead.
Confirm the required supply voltage: B2J0101 covers 5V, 9V, 12V, 18V and 24V DC, with the default ordering code corresponding to the 12V relay-output configuration; other voltages are available on request.
Decide between relay output (isolated NO/NC contacts, up to 250V AC / 10A absolute maximum) and the transistor output variant (open-drain, 12-48V DC / 10A with a built-in flyback diode) based on the load type and whether galvanic isolation is required.
If the board will be used without a case, limit the controlled circuit to a safe extra-low voltage (0-36V); a case is needed if the module will switch AC mains.
Check the operating temperature range (-20 to 60°C) and confirm it matches the installation environment, especially for automotive or outdoor-adjacent placements.

📘 Need the full method? NPN vs PNP Sensor Outputs Explained

When NOT to specify the B2J0101 — and what to use instead

The delay must be started by a sensor, switch or PLC signal rather than by power-on

Why not: B2J0101 has no trigger input terminal. The countdown starts the instant power is applied and cannot be held off, restarted or retriggered by any external signal.

Use instead: B2J0201 for level-triggered delay, or B2J0601 for multi-mode delay with edge triggers.

A delay shorter than 2 s or longer than 30 s

Why not: The on-board potentiometer covers a 2-30 second window only. There is no minute or hour range and no sub-second setting.

Use instead: B2J0601 (0-255 units in seconds / minutes / hours) or E4J0101 (0-999 x selectable unit from 10 ms to 10 h).

A panel where large motors, contactors or other strong EMI sources share the supply

Why not: B2J0101 is tested to IEC 61000-6-1 light-industry levels (500 V EFT with normal operation), not the 1 kV EFT of the IEC 61000-6-2 industrial requirement.

Use instead: Add a supply-line EFT filter or an EFT-resistant isolated supply with a cord under 3 m, or step up to E4J0101, which is measured at 2 kV EFT.

Switching a load beyond the output's rated stress

Why not: Absolute maximum is AC 250 V / 10 A (relay type) or DC 55 V / 10 A (transistor type). Normal operating stress is 8 A at AC 0-220 V / DC 30 V, or 8 A at DC 12-48 V.

Use instead: Drive an external contactor sized for the load from the B2J0101 contact rather than switching the load directly.

A safety-related power-up delay such as a guard-release or interlock timer

Why not: It is a commercial-grade timer relay with no forcibly-guided contacts and no safety rating.

Use instead: DA31 Emergency-Stop Safety Relay Module or DQSRN Safety Relay Module.

The delay setting must be numerically precise, remotely readable or logged

Why not: The delay is set by turning an analog potentiometer, with only an action LED and a power LED. There is no digit display and no digital readback of the set value.

Use instead: E4J0101, which has a 4-digit display and can be calibrated to 0.1% over USB.

Specifications we do not publish yet

We only publish a figure once we are confident it is true. The items below are still being validated through further testing and real-world customer feedback, so for now we would rather leave them open than guess. If one of them matters to your design, ask us for the latest validated status.

Electrical (load-switching) contact life under the rated 8 A load, as distinct from the published mechanical life.
Relay brand and model number.
Ingress protection (IP) rating.
MTBF.
Quantified temperature drift of the delay circuit. The manual notes EFT exposure may shift the delay slightly but gives no figure.
Operating and storage relative humidity range.
Terminal wire gauge and screw torque.
Certification status — the manual states none. Certification documents are available on request.

Frequently Asked Questions

What does the B2J0101 power-up delay relay module do?

It delays closing the relay for a set interval after power is applied. B2J0101 has no external trigger input — the countdown begins the moment power is applied, and the relay closes once the delay elapses. This is useful for sequencing equipment start-up, suppressing inrush current, or staggering loads in industrial timing applications.

What supply voltages does B2J0101 support?

B2J0101 can run from 5V, 9V, 12V, 18V or 24V DC. Supply current is below 50mA, typically around 40mA when the relay is energized. Connect the positive supply to terminal 4 and the negative supply to terminal 3.

How do I adjust the delay time?

Turn the on-board potentiometer: clockwise increases the delay, counter-clockwise decreases it, across a 2 to 30 second range. There is no trigger terminal, so the delay is measured from power-on to relay closure. The action indicator shows relay status and the power indicator confirms supply, making it easy to verify timing during setup.

Can B2J0101 switch AC mains voltage?

When supplied without a case, B2J0101 is recommended only for safe extra-low voltage control (0-36V), not AC mains. With the module cased, it can control mains-level loads; the relay output is rated up to 250V AC / 10A as an absolute maximum. Special care should be taken to prevent electric shock if a caseless board is used near AC mains.

What is the maximum load the relay output can switch?

The absolute maximum rating for the relay output is AC 250V / 10A. Under normal operating conditions the output stress is DC 30V or AC 0-220V at 8A. The output isolation voltage is type-tested to DC 1000V for 60 seconds.

Is a transistor output version available?

Yes. The transistor output variant is open-drain, rated DC 12-48V / 10A, with a built-in 10A flyback diode for driving inductive loads.

What protection features does B2J0101 have?

B2J0101 includes reverse-polarity, overcurrent, electrostatic discharge (ESD), electrical fast transient (EFT), and surge basic protections, plus a self-recovering fuse (DC 30V, 500mA) and a measured PCB creepage distance greater than 9.2mm against a 6mm requirement.

How long does the relay last?

The relay mechanical life is greater than 100,000 operations, and greater than 10,000 operations under heavy load, according to the manufacturer's specification.

What is the difference between B2J0101, B2J0201 and B2J0601?

B2J0101 starts its delay automatically at power-on with no external trigger — the simplest and lowest-cost option. B2J0201 instead starts its delay when triggered by an external level signal or pushbutton, with selectable trigger polarity. B2J0601 adds multiple delay modes (delay-off, cyclic on/off, edge-triggered, self-latching), longer delay ranges, and higher timing precision. Choose based on whether the application needs power-on timing only, external-signal triggering, or a fuller set of timing modes.

Can you provide certification documents for B2J0101?

Certification documents are available on request.