LED Sign Modules manufactured by Shenzhen Jinda Shun Technology Co., Ltd.

LED Sign Modules · Bezel-Free Series 3939B

JDS-3939B

Name: JDS-3939B
Brand: LEDjds

Square four-lens DC module, 245 lm per piece, IP68, for deep signs 120 to 200 mm behind the face.

Ingress protection: IP68Sign depth designed for: 120-200 mmInput voltage: DC 12 V / 24 V

JDS-3939B LED sign module, 39 x 39 x 9 mm

Product Overview

JDS-3939B is square four-lens DC module, 245 lm per piece, IP68, for deep signs 120 to 200 mm behind the face. The deepest-rated DC module here: at 120 to 200 mm the four lenses fire wide enough that the pitch can open up without banding. The specification below is reproduced from the manufacturer's own published sheet for this model: DC 12 V / 24 V input, 1.44 W per piece, IP68 and a published cascade limit of 20 modules single-ended, 50 modules double-ended power feed. Where that sheet publishes no figure, this page says so instead of estimating one.

Key Benefits

Published efficacy of 170 lm/W, so the wattage behind a given face area can be calculated before the sign is built rather than after.
IP68 sealing on the module body, which is the rating that decides whether condensation inside a sign cavity ends the job.
Cascade limit published as 20 modules single-ended, 50 modules double-ended power feed, so the run length and the feed points are known at drawing stage.
Designed for a sign depth of 120-200 mm, which is the single figure that decides whether the face lights evenly or shows hot spots.
5 years warranty, stated on the manufacturer's own specification sheet.

At A Glance

Family: Bezel-Free Series 3939B
Category: LED Sign Modules
Model: JDS-3939B
Series: Bezel-Free Series 3939B
Module size: 39 x 39 x 9 mm
Input voltage: DC 12 V / 24 V

Published Data Sheets

Drawings, Optical Distribution And Application Data

These are the manufacturer's own sheets for this model, reproduced as published: dimensioned drawings, the luminous distribution curve, the module pitch against sign depth, and the packing sequence. Nothing here has been redrawn or reinterpreted.

JDS-3939B technical drawing and optical data, sheet 1 — JDS-3939B - published drawing, optical distribution and application data

JDS-3939B technical drawing and optical data, sheet 2 — JDS-3939B - published drawing, optical distribution and application data

JDS-3939B technical drawing and optical data, sheet 3 — JDS-3939B - published drawing, optical distribution and application data

JDS-3939B technical drawing and optical data, sheet 4 — JDS-3939B - published drawing, optical distribution and application data

Who It Is For

Sign fabricators building channel letters and 3D luminous characters who need the depth figure before they cut the return.
Light box manufacturers sizing the module pitch against the face material.
Signage distributors who have to hold a range that covers shallow and deep cavities from one supplier.
Installers retrofitting an existing fascia where the cavity depth is fixed and the module has to fit it.

Problems It Solves

A face that shows the module pattern because the module was specified for a different depth than the sign actually has.
A run that is bright at the feed and dim at the far end because the cascade limit was never published by the supplier.
Condensation inside a sign cavity reaching an unsealed module body.
Two batches of the same model that do not match in colour on the same fascia.

Application Scenarios

Retail fascia lettering on a shop front.
Illuminated light box panels on a building entrance.
Three-dimensional luminous characters on a building parapet.
Advertising plastic characters of the kind this factory has specialised in since 2012.

Technical Features

Beam angle published as 175 deg.
Input DC 12 V / 24 V.
Rated 1.44 W per module.
Operating range -20 to +50 C, storage range -30 to +80 C.

Specification

Published Specification

Every row below is reproduced from the manufacturer's published specification for this range. Rows shown in italics are figures the specification does not publish; those are confirmed in writing rather than estimated here.

Model	JDS-3939B
Series	Bezel-Free Series 3939B
Module size	39 x 39 x 9 mm
Input voltage	DC 12 V / 24 V
Power	1.44 W per piece
Luminous efficacy	170 lm/W
Luminous flux	240 +/-3 lm at 10000K, 245 +/-3 lm at 6500K and 3000K per piece
Beam angle	175 deg
Ingress protection	IP68
Cascade limit	20 modules single-ended, 50 modules double-ended power feed
Colour options	Warm white, white, cool white, red, green, blue, yellow
Sign depth designed for	120-200 mm
Operating temperature	-20 to +50 C
Storage temperature	-30 to +80 C
Warranty	5 years
Packing	20 pcs per bag, 100 pcs per box, 1500 pcs per carton
Carton weight	22 kg
Carton dimensions	50 x 35 x 30 cm

Use Guide

Check the internal depth of the sign first. This model is published for 120-200 mm; outside that band the face either shows the module pattern or loses brightness at the edges.
Work out the run length from the cascade figure: 20 modules single-ended, 50 modules double-ended power feed. Beyond that, voltage drop starts to dim the far end and power has to be reintroduced.
Size the power supply from 1.44 W per module multiplied by the module count, then leave headroom rather than running a driver at its rated ceiling.
IP68 covers the module. The joints you make on site are not covered by it, so seal every connection to the same standard.

Quality Control

Modules are potted and sealed before the ingress rating is verified, not after assembly into a sign.
Colour binning is checked against the published bin so cartons shipped months apart still match on the same fascia.
Every batch is aged before packing; the aging rack is photographed on the factory's own process board.
Finished modules are packed in anti-static bags and cartoned to the published quantity so the count on the box matches the count on the order.

Materials

Injection-moulded housing with the optic moulded in, rather than a lens glued on afterwards.
Potting compound filling the cavity around the board, which is what carries the IP rating.
Pre-tinned lead wires on both ends for cascading, cut to the published module pitch.
3M backing tape on the models where the specification lists it, for direct mounting to the inside of a return.

Manufacturing Process

['Patch', 'A misplaced die shows as a dark lens once the face goes on.', "SMT placement of the emitters onto the module board, photographed as stage one on the factory's own process board."]
['Solder wire', 'A cold joint at the lead is the most common field failure in cascaded modules.', 'Lead wires are soldered and strain-relieved before the housing is closed.']
['Injection moulding', 'A lens bonded on after the fact separates in the heat cycle of a south-facing sign.', 'The housing and the optic are moulded together, then the cavity is potted.']
['Testing', 'A module that only fails under load passes a visual check.', 'Electrical test under load before the module leaves the line.']
['Back glue', 'Tape applied to a contaminated surface releases in the first summer.', '3M backing tape is applied to a cleaned housing on the models specified with it.']
['Aging', 'Infant mortality in LEDs shows in the first hours, not the first year.', 'Finished modules are run on the aging rack before packing.']

Certification Standards

Production follows CE, RoHS, LVD, IP68 test report, UL. Certificates are sent per product on request rather than posted publicly, because the documents a shipment needs depend on the destination market.

Customisation Options

Colour temperature selected per order from the published options rather than held as one stock colour.
Lead wire length and module pitch cut to the sign layout instead of a default spacing.
OEM and ODM work: the source site states that OEM and ODM are supported for customers in all markets.
Packing quantity per bag and per carton adjusted to how the modules will be issued on the fabrication floor.

Comparison

How It Compares With The Alternatives

A technical comparison against other ways of solving the same problem. Nothing here is a performance claim against a named competitor product.

Against a module sold without a published depth band	The depth band is the figure that decides whether the face lights evenly. This model publishes 120-200 mm. A supplier who publishes only lumens is asking you to find that band by building the sign.
Against a module with no stated cascade limit	This model publishes 20 modules single-ended, 50 modules double-ended power feed. Without that number the feed points are guessed, and the symptom - a fascia that dims towards one end - looks like a bad batch rather than a wiring decision.
Against an IP rating quoted for the range rather than the model	The rating here is IP68, published against this model. Note that it covers the module body as supplied and not the joints made on site.
Against another family in this range	See the LED Sign Modules page for what this family does that the others do not, and the related products below for the nearest alternatives.

Questions

JDS-3939B Questions

What sign depth is JDS-3939B designed for?

The published specification gives 120-200 mm. That figure is the distance between the module and the inside of the face, and it is the first thing to check before anything else about the model.

How many JDS-3939B modules can run from one feed?

The specification publishes 20 modules single-ended, 50 modules double-ended power feed. Past that limit voltage drop dims the far end of the run, so power is reintroduced rather than the run extended.

What is the ingress rating?

IP68 on the module itself. Connections made on site are not covered by the module rating and have to be sealed separately.

What is the warranty?

5 years, as published on the manufacturer's specification.

Can it be supplied in a colour temperature that is not listed?

The published colour options are: warm white, white, cool white, red, green, blue, yellow. Anything outside that list is a custom request and is confirmed in writing before the order, not assumed.