Spacing 20mm Pixel Strings in Backlit Letters: What a 60° Beam Can Tell You
Quick decision
Choose diffuser depth before choosing centre spacing. With the page's 60-degree beam and an illustrative 50mm standoff, simple cone geometry gives 2×50×tan30°≈57.7mm coverage diameter. This is not a recommended pitch: the lens, diffuser, reflection and colour change the result. Test straight strokes, narrow strokes and corners together.
Published facts and evidence boundary
| Parameter | Published or derived value |
|---|---|
| Published point | 20mm body; three SMD5050 LEDs; RGB |
| Beam | 60 degrees; no post-diffuser uniformity rating |
| Electrical/protection | DC5V; 0.3W line; IP67 point body |
| Illustrative cone | At assumed 50mm depth: 2×50mm×tan(30°)≈57.7mm |
| Mock-up load | If 0.3W/point, 30 points = 9W and 1.8A at DC5V |
| Must be measured | Actual pitch, hole, diffuser, dark gaps and joint protection |
Estimate the light footprint before the centre pitch
A 60-degree beam is not a published optimum pitch for a backlit letter. In an ideal cone model with a hypothetical 50mm source-to-diffuser distance, footprint diameter is about 57.7mm. The 50mm depth is an example, not this product's specified install depth; lens, reflective cavity and colour change real overlap.
Make a mock-up with a straight stroke, narrow stroke and corner, then view it from the closest buyer position. If the stroke is narrower than the body or the border clips the footprint, change cavity depth, reflection or product type before simply adding more points.
Keep 20mm body size separate from the drilling size
LIKELIGHT lists 20mm, three SMD5050 LEDs, 60 degrees, DC5V and IP67. The 20mm body is not automatically the drill hole, clip size or lit aperture; three LEDs also do not prove three separately controllable pixels.
Install several points in the real lens and panel to record centre pitch, rear fixing, border occlusion and replacement access. The page heading says APA102C and the IC field APA102: if animation is needed, freeze the delivered chip and map independently of the optical test.
Use the optical mock-up to check its 5V load
The page lists 0.3W without describing a particular operating scene in this summary. If it applies per point, a 30-point sample gives 9W and a theoretical 1.8A at DC5V. This is sample arithmetic, not a permissible or maximum string length.
A tighter pitch increases point count and branch current for a given sign area. Record actual count, route and loaded voltage at the sample's far end; cable loss rises with current and path resistance. First approve visual continuity, then divide feeds for the agreed number of points.
Animation follows optical fit, not the other way round
The heading says APA102C and the IC field APA102; neither makes each LED a separate address. For a uniformly coloured letter, stroke consistency and serviceability come first. Point-by-point movement still requires the delivered IC, data direction and controller to be established.
APA102-family control usually has separate clock and data, but photographs cannot prove this string's connector pinout. Once positions are fixed, test first and last points and the actual programme; a correct map cannot hide an optical dark band.
IP67 points do not waterproof a whole sign
IP67 for the points helps select a part, but says nothing automatic about hole edges, lead exits, field joints or supply enclosure. Water paths through the sign back and the method of replacing a point matter to service cost.
Mount the test in the real letter shell, checking harness support, exit and the cleaned diffuser appearance. An outdoor build without protected joints, drainage or access should not pass just because the point body is rated IP67.
Conditional project decision table
| Project condition | Decision and evidence |
|---|---|
| Narrow strokes seen close | Test straight and corner sections; remove visible dark zones. |
| Large lettering viewed afar | Judge pitch from real viewpoint, not equal spacing based on 20mm diameter. |
| Shallow indoor letter | Verify point, clip and rear clearance before ordering. |
| Outdoor channel letter | Inspect holes, joints, drainage and power as well as IP67 bodies. |
| Larger face with more points | Apply the conditional 0.3W figure to actual count and measure loaded ends. |
| Individual animation needed | After optical approval, freeze IC, mapping and clock/data pinout. |
LIKELIGHT 20mm string as a letter-spacing prototype
The 20mm RGB point with a 60-degree beam is worth testing in letters with enough cavity depth and accessible mounts. The 57.7mm cone at a hypothetical 50mm depth only sets a mock-up range; actual pitch follows diffuser, stroke geometry and viewing distance.
It is a poor fit for strokes thinner than the body if density alone is expected to fix shadowing, or for a sign whose outdoor protection relies solely on point IP67. Approve a short corner-inclusive sample, then order to measured count.
Information required before quotation
- letter shapes, narrow strokes and viewing distance
- cavity depth, diffuser and reflective backing
- candidate pitch and actual sample point count
- hole and mounting fit for the 20mm body
- DC5V feed zones and loaded-end measurement
- uniform colour or mapped animation
- outdoor joints, drainage and service access
- sample and production quantities and timing
These inputs connect dark-band control, physical fit, point quantity and feeds; cone geometry cannot replace a real uniformity test.
Frequently asked questions
Is 57.7mm the recommended pitch?
No. It is an ideal projection for an assumed 50mm depth and 60-degree beam; test the actual diffuser.
Do three LEDs make three pixels?
Emitter count and pixel mapping are separate specifications.
Can 30 points be fed from one end?
9W and 1.8A are conditional totals; judge from route resistance and loaded-end voltage.
Does IP67 make the outdoor letter waterproof?
Point rating does not cover holes, joints, drainage or the supply box.
