Yes.Analogue is like a POT, right? Variable R?
Yes, but T1 is in analogue mode.I'm PWM switching M1, isn't that switch mode?
Yes.Analogue is like a POT, right? Variable R?
Yes, but T1 is in analogue mode.I'm PWM switching M1, isn't that switch mode?
What about adding a small capacitor between Z1 & T1, and switching out T1 for a FET? So the cap pulses at different rates for a digital signal to drive the gate?Yes.
Yes, but T1 is in analogue mode.
I'm unclear what you're trying to do. Since LED1 is in series with LED2 then the MOSFET would not be on the low side of LED2.Keep bottom half the same except switch the MOSFET to the low side...
I don't know if I'd go that route. The 555 is a good learning circuit and was the thing when it came out but there are better ways of doing a PWM. Have a look at the SG3525 IC or one of the variants. You can even drive the mosfets directly. A Google of the part number will give quite a few proven circuits for using it in PWM.Hey, looking into 555 timers for a pulse generator.
Great Scott! Haha thanks man ill give it a look up. I gave the schematic a glance but it'll take me quite some time to decipher what's going on lol but that's just the way it goes when you're new, I think seeing it in action will help, thanks again!I don't know if I'd go that route. The 555 is a good learning circuit and was the thing when it came out but there are better ways of doing a PWM. Have a look at the SG3525 IC or one of the variants. You can even drive the mosfets directly. A Google of the part number will give quite a few proven circuits for using it in PWM.
https://www.st.com/en/power-management/sg3525.html
Not lately. You would need two circuits though if you want to PWM directly to 2 panels, like your showing in your sketch. To do the same with a 555, you would also need 2 circuits.Have you used one of these before?
The SG3525 is only a timing and switch signal generator, to generate the gate signal. The mosfet D/S you chose is what would handle the 60V. He is/was using a low side mosfet, but that is subject to change.The maximum allowable supply voltage for the SG3525 is 40V, so it won't survive in your circuit if the CC driver is supplying 60V
That is what I was saying earlier but didn't explain it good enough I guess. Instead of panel 1 and 2, I should have said row 1 and 2. Shutting off every other (or how ever you arrange them) will be the same as dimming a whole area. When every row of LEDs is on it's bright, but when certain rows, on the same panel, are off it isn't as bright. This could be done with either mosfets or even a relay.I want different LEDs populated on a PCB to be dimmed up or down independent of each other. Not an entire grow area, just the light itself.
Agreed, but its supply pins are shown connected between the +ve rail (60V) and ground.The SG3525 is only a timing and switch signal generator, to generate the gate signal.
I await your solution. If the LED1 and LED2 arrays are effectively in parallel rather than in series then, because the forward voltage of LED1 is much lower than that of LED2, LED1 pulls down the voltage of the CC source below the point where LED2 can operate, unless some energy-wasting voltage dropper is inserted in series with LED1.Not having them in series.
I doubt you can run a buck converter from the output of a CC source. Wouldn't the buck converter cost nearly as much as a second CC source?Buck converter?
As I said in post #120, "With the LED1 and LED2 arrays in series then, even if the PWM duty cycle for LED1 is different from that of LED2, the average current in LED1 will be the same as in LED2, i.e the dimming will not be independent." IMO the same goes for however you try dimming multiple arrays/channels arranged in series ..... you get the same current in each array/channel.Have you any info on what I'm thinking would be an issue if going the series route?
If the supp channels are all in series with the main channel then all channels pass the same current. Where else can the current go?So you're saying that the supp channel MOSFETs, when operating at a lower duty cycle than the main channel MOSFET, will not act as a variable resistors reducing averaged current flow though the supp array?
No. If any one of them restricts the current, that will restrict the current through the others.Main light gets same current no matter what 1 & 2 (or 3 or 4 or 5) are having flowed through them.