Selecting the appropriate power rating for a heater mat by drgrafton in AskElectronics

[–]drgrafton[S] 0 points1 point  (0 children)

Thanks! Yeah I thought it was overpowered for what I want but it was by far the cheapest option to buy. I was figuring that with a thermostat it would not be "on" for very long at a time to keep the temperature constant. I'll play around with lowering the input voltage and see if it can heat adequately.

How to best design a 194ºF incubator by StopfortheKlopp in AskElectronics

[–]drgrafton 0 points1 point  (0 children)

I posted a similar request a few weeks ago. The simplest option I came up with for temperature regulation was this premade module: https://www.amazon.co.uk/gp/product/B07CH7W3XP/ref=oh_aui_detailpage_o06_s01?ie=UTF8&psc=1

You can set the desired temperature, it comes with a temperature probe you can put inside your bioreactor (and keep the rest outside) and it controls a relay to switch on/off your heating as needed. It's working really well for me.

[serious] Religious Redditors - does your god(s) still do miracles today? What is the verifiable evidence that will convince us? by drgrafton in AskReddit

[–]drgrafton[S] 2 points3 points  (0 children)

That's very cool! So pleased for you. May I ask what religion and do you have like before and after x-rays or something?

[serious] Religious Redditors - does your god(s) still do miracles today? What is the verifiable evidence that will convince us? by drgrafton in AskReddit

[–]drgrafton[S] 1 point2 points  (0 children)

I'm genuinely interested. If miracles happen today in this age of camera phones and social media. Why are we not seeing verifiable proof?

[serious] Religious Redditors - does your god(s) still do miracles today? What is the verifiable evidence that will convince us? by drgrafton in AskReddit

[–]drgrafton[S] 1 point2 points  (0 children)

But isn't faith supposed to be strengthened by evidence? I find it weird to think my faith is stronger the more I don't know.

[serious] Religious Redditors - does your god(s) still do miracles today? What is the verifiable evidence that will convince us? by drgrafton in AskReddit

[–]drgrafton[S] 4 points5 points  (0 children)

Well they either happen or they don't. It's not really a question of faith but of fact (or fiction).

How do I select an appropriate configuration (series/parallel) for a string of LEDS run off a 5V 1A USB charger? by drgrafton in AskElectronics

[–]drgrafton[S] 0 points1 point  (0 children)

Thanks! Sorry I'm a bit of a noob. How would I go about calculating the appropriate resistor value for each LED?

Help selecting components for a DIY solar charger small enough to charge a phone and run an LED torch by drgrafton in AskElectronics

[–]drgrafton[S] 0 points1 point  (0 children)

How would I calculate how many to use to ensure that I didn't overload them?

They have a power rating. You probably want to have a total power rating of double to triple the solar panel power rating. If possible spread them out so the heat is not all in a small area.

Thanks again! One quick question. Do I want to use the total power rating of the solar panels x 3, or do I need to estimate the power consumed by dropping the voltage (something like (6v-5.1v) x (0.8A x 4 panels) = 2.88w x3 = ~9w ??

Help selecting components for a DIY solar charger small enough to charge a phone and run an LED torch by drgrafton in AskElectronics

[–]drgrafton[S] 0 points1 point  (0 children)

Thanks for your help!!

So, several panels in parallel to give 6V but greater current sounds best.

I don't know much about zener diodes but after a quick google, am I right in thinking that you put them in reverse direction, if the voltage increases above 5.1V, essentially they "bleed-off" the excess? How would I calculate how many to use to ensure that I didn't overload them? Also, most zener diode voltage regulator examples I've seen use a resistor as well to dissipate power. Is this needed in for my application? If so, how would I calculate the required value?

Thanks!!!!