BL-TRIAC logarithmic dimming: keep the default curve or send points
The BL-TRIAC note already names the dimming law: logarithmic by default, and open to a project change. The decision on a new LED supply is whether that printed law is the one you ship, or whether the program has brightness points the default will miss.
Jarwey supplies BL-TRIAC as a project module. The note prints no gamma, no knee table, and no soft-start milliseconds. This page does not invent them.
Phase-cut wiring into a CV or CC supply is a separate note: leading / trailing edge. Handing Jarwey the load and the wall control is the custom-requirement note. A module quote versus a wall-system quote is the price-scope note. What a sample order freezes is the small-batch note. Strip 16 kHz, magnetic track 10 kHz, and constant-current 1 kHz are the frequency rows. Pin 6 versus pin 9 is the PWM pin split. Those tables stay in those pages.
A 0–100% duty cycle is the PWM span, not the law
| Line in the note | What it prints | What it does not decide |
|---|---|---|
| Dimming curve | Logarithmic by default; a custom law is allowed | This is the line to freeze. A linear law is not printed as a second factory mode |
| PWM duty | 0% minimum, 100% maximum | Span of the PWM output, not a claim that brightness tracks the knob in a straight line |
| Supply voltage | 12 V minimum, 15 V typical, 30 V maximum | Does not set the curve shape |
| Supply current | 5 mA typical, 10 mA maximum | Does not set the curve shape |
| Soft start | Present at power-up | No duration is printed. Leave it out of the curve table |
| Signal path | RC filter, op-amp conditioning, MCU AD, dimming curve, PWM | The curve sits after the AD conversion and before the PWM, for deep dimming |
Keep the printed law, or send the points
| What the program must freeze | Action |
|---|---|
| Knob or phase-cut travel may follow a logarithmic feel, and no brightness points are specified | Keep the default logarithmic curve |
| Brightness is specified at given phase-cut or knob positions, and the default misses them | Send those points to Jarwey and have the curve changed |
| The strip, magnetic-track, or constant-current fixture is on the wrong PWM rate | Leave the curve alone. Strip: R19 = 10 kΩ, 16 kHz. Magnetic track: R18 = 10 kΩ, 10 kHz. Constant-current fixture: 1 kHz, resistor cell blank. See the frequency note |
| PWM must leave on the high-side pin or on the MOSFET pin | Leave the curve alone. Pin 6 and pin 9 are in the pin-split note |
| Turn-on surge, and someone wants a custom ramp time | The note only says soft start exists at power-up. A made-up millisecond is not a finished curve change |
A listed wall control still leaves the curve open
The note names controls that can be evaluated on the bench: Opple leading-edge P068102, Panasonic WMY549, Legrand VRCM2, Siemens 5UH82223-NC01, Lutron leading-edge QSGR-3P, Siemens 5WG1 528-1D801, Schneider leading-edge L5504D2A. Bench evaluation is required. A model match is not a drop-in replacement and not an unverified pin-to-pin swap. A control that runs does not mean the default logarithmic law already matches that panel’s brightness feel. A wall model absent from the note does not inherit another panel’s curve.
The note describes deep-dim light as fine, stable, smooth, and free of jitter. That sentence has no gamma. It does not replace brightness points.
Custom work, price, and samples on this one line
- Custom. To change the curve, send the brightness points, the load (strip, magnetic track, or fixture), and the wall-control model. Jarwey does the design, the scheme, and the delivery from that request.
- Price. The line under evaluation is the curve on this module. The wall controls are bench references. The imported wall-system premium does not have to be paid again just to change one curve.
- Delivery. Samples and small lots follow the project. On the sample, check whether the default logarithmic law already covers the feel, then decide whether a change is required.
Curve checklist
- Write down whether the default logarithmic law is accepted, or brightness points already exist.
- If points exist, send them with the project. The default law does not land on those points by itself.
- Treat 0%–100% as the PWM span. Do not record it as linear brightness.
- Freeze the frequency row (R18, R19, or 1 kHz) separately from the curve type.
- Freeze pin 6 versus pin 9 separately. ACL and VCC have no pin numbers in the note. Do not assign them.
- Quote soft start only as “present at power-up.” Do not add a millisecond the note never printed.
- Controls on the printed list still need a board check. Request the datasheet from Jarwey.
Product page and the note
- Product: BL-TRIAC multi-function TRIAC dimming module
- Note: BL-TRIAC module note. For a maintained copy, ask Jarwey for the datasheet.
Send whether the default logarithmic law is accepted, the brightness points, the load name, and the wall-control model to Jarwey: kerry.w@jarwey.cn · contact. Scheme, application support, samples, and schedule can be handled on that request.
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