Siri Smart
12:42 Thursday, 18 June 2026
Current Wx: Temp: 71.29°F Pressure: 997hPa Humidity: 84% Wind: 17.4mph
Words: 957
I spent some time this morning with the Siri app in MacOS 27, asking about low-voltage, DC LED lighting. The experience was very much on par with the discussions I've had on ChatGPT and Claude.
The conversation veered into our HVAC design as well, and it seemed as informative as Claude and ChatGPT were in that topic as well.
Like both of those other AI products, Siri tends a bit toward the verbose, but it doesn't have the gratuitous obsequiousness of the other two. It does ask questions to continue the conversation, which the others do as well.
I haven't asked it anything about things like AppleScript, or how to write a formula in Numbers, but that's another area I'll be exploring.
Had a very pleasant Zoom call with the representative from CleanLife & ATX LED about low-voltage DC lighting solutions. We'll have another meeting with Mitzi on the call to talk about design solutions before we get a quote. He's confident that we'll probably save money on our lighting install, simply from the wiring.
I'm planning to use a Zigbee system, with their Kinetic products, rather than the ATX-specific design. That means we'll be using constant voltage versus constant current, which also means that dimming will be achieved with pulse width modulation (PWM), which is supposedly the source of flicker, I mentioned the other day.
For funsies,here's part of my chat with Siri, responding to the question:
Can you tell me what the practical difference is between a "constant current" and "constant voltage" DC LED lighting system would be? Apparently the "constant current" system can dim LED bulbs more, but as a practical matter it's not significant. Is that correct?
Answer:
You are entirely correct that for most residential applications, the practical difference in dimming between the two systems is negligible. While Constant Current (CC) systems are technically superior at ultra-low dimming levels, modern Constant Voltage (CV) systems—especially at 48V DC—use high-frequency dimming that is completely imperceptible to the human eye. The real practical difference for your home build comes down to wiring flexibility and fixture types, rather than how dim the lights can get.
THE PRACTICAL DIFFERENCES
| FEATURE | CONSTANT VOLTAGE (CV) | CONSTANT CURRENT (CC) |
|---|---|---|
| How it Works | Delivers a fixed voltage (e.g., 48V); the current varies based on how many lights are on. | Delivers a fixed current (e.g., 700mA); the voltage adjusts automatically. |
| Best Used For | LED tape, linear lighting, and flexible systems where you might cut strips to length. | High-power individual fixtures, like architectural downlights or exterior floodlights. |
| Wiring Flexibility | High. You can wire lights in parallel (like a standard home). Easy to add or remove lights later. | Low. Lights must be wired in a specific series loop. If one light fails, the whole loop can go dark. |
| Dimming Method | Uses PWM (Pulse Width Modulation)—turning the light on and off thousands of times per second. | Uses CCR (Constant Current Reduction)—actually lowering the electrical flow to the diode. |
THE DIMMING MYTH: DOES CC REALLY DIM BETTER?
Technically, yes. A Constant Current driver can dim an LED down to 0.1% smoothly because it is physically choking the electricity flowing into the diode.
However, modern Constant Voltage systems use PWM (Pulse Width Modulation). Instead of lowering the power, they flicker the light on and off so fast (thousands of times a second) that your brain perceives it as "dim." Unless you are shooting high-speed, slow-motion video in your house, you will never notice the difference. Both will dim down to 1% perfectly for your eyes.
WHICH ONE SHOULD YOU CHOOSE FOR YOUR BUILD?
For a 48V DC residential system, Constant Voltage (CV) is almost always the better choice for the following reasons:
1. The "Christmas Light" Effect: Constant Current requires wiring fixtures in a series. If one CC downlight fails, the circuit breaks, and every light on that line goes out. CV is wired in parallel, so if one light dies, the rest stay on.
2. Flexibility: With CV, if you decide later to add one more puck light over a kitchen counter, you just tap into the existing 48V line. With CC, you would have to completely recalculate the electrical load for the whole chain.
3. The 48V Advantage: Because you are already using 48V (instead of 12V or 24V), you won't suffer from "voltage drop" (where lights get dimmer at the end of a long wire), which used to be the only real downside of Constant Voltage.
Are you looking at a specific brand of 48V fixtures (like WAC, PureEdge, or a proprietary smart home brand), or are you still in the exploratory phase?
==============================
That also shows the question at the end.
My Tinderbox Export Template for the marmot doesn't handle tables. When I copied and pasted the response into Tinderbox, a very nice RTF table appeared in the text of the note that is this post.
Rather than try to figure out how to revise the template, I made a screenshot of the table and asked Siri for the html to re-create it.
Let's see how that works.
Update: That worked pretty well. It also gave me some css to make it look better (add the lines and so on), but I omitted that because I have no idea what I'm doing! I'll have to check out the RSS and see how that turned out.
✍️ Reply by email