D3 looks like protection against putting too much voltage in, and D2 looks like it's just using the diode's forward voltage of 0.7V to drop some voltage.
(Disclaimer, I'm not an EE bla bla bla)
If you fed 20V in, D3 would be open, and it would connect power directly to ground.
[QUOTE=nikomo;46699030]D3 looks like protection against putting too much voltage in, and D2 looks like it's just using the diode's forward voltage of 0.7V to drop some voltage.
(Disclaimer, I'm not an EE bla bla bla)
If you fed 20V in, D3 would be open, and it would connect power directly to ground.[/QUOTE]
The +15V is constant and not anything I control. The pins you see (1-6) are actually a 8-pin RJ45 connector, where pins 6, 7 and 8 are not used. Pin 1 and 2 are used for LEDs that show if the fogging machine is heating or not and if it's ready to output smoke.
My final plan is to have an Arduino that receives the status of both LEDs, controls the output of pin 4 from 0-10V depending on what I want (it regulates the fog machine output) and this all using DMX512, but I'll most likely buy an Arduino shield for the DMX bit, I just need to get this circuit working but I'm not sure how I can regulate the voltage on pin 4 using an Arduino. In the big diagram you can see LM358's being used, and I suppose this is what I should be using too, but I don't know how I would wire it to make it work.
Also, if I want to get this on a circuit board, what do you guys recommend? I've read that ordering a single circuit board is too expensive, but I don't think I have the equipment to create my own equipment board. Currently I'm just using one of those breadboards but I want to end up implementing this into a flightcase.
[QUOTE=Cyberuben;46699144]The +15V is constant and not anything I control. The pins you see (1-6) are actually a 8-pin RJ45 connector, where pins 6, 7 and 8 are not used. Pin 1 and 2 are used for LEDs that show if the fogging machine is heating or not and if it's ready to output smoke.
My final plan is to have an Arduino that receives the status of both LEDs, controls the output of pin 4 from 0-10V depending on what I want (it regulates the fog machine output) and this all using DMX512, but I'll most likely buy an Arduino shield for the DMX bit, I just need to get this circuit working but I'm not sure how I can regulate the voltage on pin 4 using an Arduino. In the big diagram you can see LM358's being used, and I suppose this is what I should be using too, but I don't know how I would wire it to make it work.
Also, if I want to get this on a circuit board, what do you guys recommend? I've read that ordering a single circuit board is too expensive, but I don't think I have the equipment to create my own equipment board. Currently I'm just using one of those breadboards but I want to end up implementing this into a flightcase.[/QUOTE]
D3 limits the output to 10V, instead of 15V.
D1 and D2 are to prevent forward biasing of the base-collector junction of the transistor.
When SW1 is open the transistor is on pulling the output close to 0V, when it's closed the transistor turns off and the output goes to 10V (15V without D3).
To generate a variable voltage from a micro you can use PWM which is exactly what is going on in the larger schematic, R10 and C4 produces a DC voltage from the PWM, this is then amplified by the LM358, using R11 and R12 to set a gain of 2, the result is a roughly 0 to 10V range.
[QUOTE=nuttyboffin;46697034]I have one you could have for £50 including P&P[/QUOTE]
Mind giving me some details please?
[editline]12th December 2014[/editline]
Operation dew heater was a partial success. Only caught fire three times :dance:
[QUOTE=Leestons;46700370]Operation dew heater was a partial success. Only caught fire three times :dance:[/QUOTE]
I'd call that a bonus feature.
[QUOTE=Leestons;46700370]Mind giving me some details please?
[editline]12th December 2014[/editline]
Operation dew heater was a partial success. Only caught fire three times :dance:[/QUOTE]
I shall do next week. I'm going away for a good few days.
[QUOTE=nuttyboffin;46701102]I shall do next week. I'm going away for a good few days.[/QUOTE]
Thanks! I might buy it, not sure if I really should get a scope yet as I have no idea what I'd use it for.
[QUOTE=Leestons;46701268]Thanks! I might buy it, not sure if I really should get a scope yet as I have no idea what I'd use it for.[/QUOTE]
Mostly for measuring voltage over time!
But in all seriousness, a scope is an essential tool for working with electronics, and greatly helps with looking into a circuit to check out what is going on.
[QUOTE=Leestons;46701268]Thanks! I might buy it, not sure if I really should get a scope yet as I have no idea what I'd use it for.[/QUOTE]
I use my scope for practically everything, even for simple DC measurements it can be very handy allowing you to see noise and ripple that otherwise could be missed with a meter, also I think it makes electronics easier to learn since you get instant visual feedback rather than staring at numbers.
Just bought a SainSmart Uno R3, a DMX shield from Conceptinatics and €16 worth of components. Thanks to nuttyboffin and Chryseus
I ordered a SainSmart Mega a few days back from eBay, can't wait for that to arrive, seems cool.
Then I also ordered a 3.2" LCD + touch screen + SD reader module that fits on the Mega, a ton of breakaway headers, and 2 0.96" blue OLED screens.
One screen is I2C, one screen is SPI.
And I have one of those Arduino kit things coming from Aliexpress... at some point. Taking a while to arrive. I hope it comes next week, because after that, the postal system is just screwed and the post office is way, way too full of people.
One of my packages has an estimated arrival date of December 24 :v:
The amount of not-happening on that estimate, cannot be measured.
The OLED screens seemed kind of cool when I looked at them, and they were cheap enough that I just grabbed a few. Didn't bother to figure out how they work yet though, apparently you need to send in raw data, they don't have any sort of built-in font crap. Can't be too hard.
Whoops. I paid $30 for a 9800 mah 12v lithium ion battery pack and charger from eBay. I then googled "9800 mah to ah" because I always second guess myself when I do math on my head. One of the first results was a page explaining how that exact battery only had about 30% of the advertised capacity. Then I got a notification from eBay saying my order shipped.
I hate when forget that the Chinese can be assholes on eBay.
I'll probably find a use for it in a lower power situation, though for my DIY boom box I'll probably stick with a small, SLA motorcycle battery.
Real lithium or NiMH batteries of that kind of capacity are always very expensive, you can't beat lead acid when it comes to price per Ah.
[QUOTE=nikomo;46705763]
The OLED screens seemed kind of cool when I looked at them, and they were cheap enough that I just grabbed a few. Didn't bother to figure out how they work yet though, apparently you need to send in raw data, they don't have any sort of built-in font crap. Can't be too hard.[/QUOTE]
[URL="https://code.google.com/p/u8glib/"]U8GLib[/URL] is amazing at driving displays. It supports a ton of different display types and doesn't use an unreasonable amount of ram or program storage.
[QUOTE=nikomo;46705763]The amount of not-happening on that estimate, cannot be measured.
The OLED screens seemed kind of cool when I looked at them, and they were cheap enough that I just grabbed a few. Didn't bother to figure out how they work yet though, apparently you need to send in raw data, they don't have any sort of built-in font crap. Can't be too hard.[/QUOTE]
I have one of the [url=https://www.adafruit.com/products/931]adafruit OLED screens[/url], their graphics library works a treat.
Admittedly I decided halfway through using that that making a decent user interface was hard so I swapped out the screen for an ethernet jack and controlled it from my website.
[t]http://u.cubeupload.com/Chryseus/0QIsWj.jpg[/t]
Am I the only one that prefers to work late at night ?
[QUOTE=Chryseus;46706946][t]http://u.cubeupload.com/Chryseus/0QIsWj.jpg[/t]
Am I the only one that prefers to work late at night ?[/QUOTE]
I prefer it too but I don't really have the lighting for it.
I got some LED strips above my desk but they're not very bright, I really should do something about that.
[QUOTE=Chryseus;46706966]I got some LED strips above my desk but they're not very bright, I really should do something about that.[/QUOTE]
MORE AMPS!!
[QUOTE=Leestons;46706956]I prefer it too but I don't really have the lighting for it.[/QUOTE]
For the few times I've worked at my bench rather late, the old fluorescent tubes I have give this weird green glow that's kinda mind numbing.
Course that's just because the filters on them are twenty+ years old.
I looked into getting some LED strips a few months ago but could only find them in lengths of like 5 meters or more. I don't need 5 meters, I don't even need 5 feet!
I could make my own but... effort.
[QUOTE=Leestons;46707034]I looked into getting some LED strips a few months ago but could only find them in lengths of like 5 meters or more. I don't need 5 meters, I don't even need 5 feet!
I could make my own but... effort.[/QUOTE]
There's some LED strips that are [URL="http://www.amazon.com/StreetGlow-ULST19WH-White-Flexible-Trimmable/dp/B00GZL9HPM"]trimmable[/URL].
[QUOTE=LoneWolf_Recon;46707091]There's some LED strips that are [URL="http://www.amazon.com/StreetGlow-ULST19WH-White-Flexible-Trimmable/dp/B00GZL9HPM"]trimmable[/URL].[/QUOTE]
I'm pretty sure ~all 5m led strips are trimmable. Most is wired with 3 leds in parallel (12V), so you can cut at every third led. And you can easily find 1m led strips.
I think I'll come up with a better design for this heater tomorrow. I think when the tape gets hot it is shrinking, which then makes the nichrome wire touch and short, leading to flames. Everything below this hot spot is cold so it must be a short.
Hey, if anyone can add me on steam and help me with a few questions about transistors, voltage and stuff I'd be really thankful. I'm working on an arduino project and I'm pretty lost about parts.
[QUOTE=Maksim;46707500]Hey, if anyone can add me on steam and help me with a few questions about transistors, voltage and stuff I'd be really thankful. I'm working on an arduino project and I'm pretty lost about parts.[/QUOTE]
Post it here so whoever runs into the same problem in the future won't have to ask again.
[QUOTE=Maksim;46707500]Hey, if anyone can add me on steam and help me with a few questions about transistors, voltage and stuff I'd be really thankful. I'm working on an arduino project and I'm pretty lost about parts.[/QUOTE]
It's just as easy (or even easier) to help you in this thread. And you'll get more help as more people will see it.
What's your project?
So I start Computer Engineering next semester...
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