Electrical Engineering V2 - Developers

[QUOTE=pentium;46684713]Hmmmm. How to drive ten seven segment numerical displays from one microcontroller.[/QUOTE] Lots of shift registers?

[QUOTE=pentium;46684713]Hmmmm. How to drive ten eight segment numerical displays from one microcontroller. [IMG]http://i11.photobucket.com/albums/a166/ballsandy/clock_concept.png[/IMG] Edited: or we find a way to have the microcontroller spit out IRIG timecode so I don't have to gut this beautiful clock. [IMG]http://i11.photobucket.com/albums/a166/ballsandy/CGS_0827.jpg[/IMG][/QUOTE] So... many... chips? What are they all?

7400 logic. The underside is amazing. It's all wire wrap. [IMG]http://i11.photobucket.com/albums/a166/ballsandy/CGS_0829.jpg[/IMG] Actually, now that I'm looking at that, I realize the shift registers are already installed.

Where'd you pick up that beauty?

From Sphere Research's annual free day, along with all that other test gear I got in August.

You could use 4511's to drive the 7 segments, and then use a shift register to enable the latches. That'd be 4 data pins for the 4511 and a few for the shift register.

[QUOTE=pentium;46685224]From Sphere Research's annual free day, along with all that other test gear I got in August.[/QUOTE] Wish you told me about that... Not that I would have gone to Kelowna (no car), but I could have given you a list (photomultiplier tubes mostly). [editline]10th December 2014[/editline] [QUOTE=scratch (nl);46684606]I have tried this setup with various capacitors (100, 470 and even 1000 uf), but none of them seem to help enough to fix the reset issue. I tried putting one from my V+ rail to the Vin pin onto the arduino nano as well but that just results in a short pulse of power to the nano after which it stays off. could it be due to them having dried up? Is there an easy way to check this (without an ESR meter)? They aren't stored in particulary high temprature places, just in plastic bags within a wooden box.[/QUOTE] Looking at the [URL=http://arduino.cc/en/Main/arduinoBoardNano]data sheet[/URL] that massive 6v battery of yours is at the lower limit of what the board will tolerate. Some sort of servo induced voltage drop?

[QUOTE=Chryseus;46683407]Yeah it's crazy, people ordering now are going to be waiting until late January, glad I didn't wait until Christmas to order :v: A current transformer doesn't output a high voltage as long as it's connected to a current meter, since V = I/R, if you was to disconnect the current meter while there is current going through the CT then it would produce high voltage which is why CT's are kept shorted when measurements are not being made.[/QUOTE] Well I really meant current (it's rated for 100A max) and what I meant by kill myself is that I can't shut off the power to the house and I don't want to risk opening up the panel and shorting something on accident.

[QUOTE=papkee;46686052]Well I really meant current (it's rated for 100A max) and what I meant by kill myself is that I can't shut off the power to the house and I don't want to risk opening up the panel and shorting something on accident.[/QUOTE] Get a mains cord and remove the plug, cut the insulation back a bit a put the current transformer on and wire the plug back up. That way you can just unplug it and remove the CT when done. Just don't touch it while it's on and there is no shock hazard.

[QUOTE=Cakebatyr;46685428]Wish you told me about that... Not that I would have gone to Kelowna (no car), but I could have given you a list (photomultiplier tubes mostly). [editline]10th December 2014[/editline] Looking at the [URL="http://arduino.cc/en/Main/arduinoBoardNano"]data sheet[/URL] that massive 6v battery of yours is at the lower limit of what the board will tolerate. Some sort of servo induced voltage drop?[/QUOTE] welp, that can be a very good possibility :v: I have a feeling you found my problem. I will try it out with a higher voltage source soon. [editline]10th December 2014[/editline] right so I changed shit around a bit. I'm using a 9V battery pack now, which is connected to the arduino and a [URL="https://www.fairchildsemi.com/datasheets/LM/LM7805.pdf"]voltage regulator[/URL] to power the sensor and servo's at 5V. I do get a bit of controll when I power it up, but the servo's freak out most of the time and the voltage regulator got pretty damn hot within 10 seconds (with a small heatsink on it). [editline]10th December 2014[/editline] so far this certainly has been a project with interesting bugs I gotta admit. [editline]10th December 2014[/editline] perhaps it could be thermal overload protection kicking in? From what I gather, the power regulator probably generates around 2W of heat, and considering how hot the heatsink got so quickly...

Does anyone here know how many inputs an Arduino Uno can take? I want to use 10p dipswitches so I can define a DMX channel from 0 - 511, but I am not sure if the Arduino Uno supports this many inputs. Or, is there any way to create a digital value like this that the Arduino can receive based on analog input (just high-low)?

[QUOTE=Cyberuben;46687335]Does anyone here know how many inputs an Arduino Uno can take? I want to use 10p dipswitches so I can define a DMX channel from 0 - 511, but I am not sure if the Arduino Uno supports this many inputs. Or, is there any way to create a digital value like this that the Arduino can receive based on analog input (just high-low)?[/QUOTE] Or you could try [url=http://en.wikipedia.org/wiki/Multiplexer]Multiplexers[/url] [editline]10th December 2014[/editline] [QUOTE=Cakebatyr;46680357]The Rigol 1052D was $800 when it first came to the market, but the 1054Z is starting at US$329. So its a fantastic deal. [editline]9th December 2014[/editline] Also Rigol doesn't acknowledge Canada's existence.[/QUOTE] Googles currency converter showed that €360 was about $450.

[QUOTE=Cyberuben;46687335]Does anyone here know how many inputs an Arduino Uno can take? I want to use 10p dipswitches so I can define a DMX channel from 0 - 511, but I am not sure if the Arduino Uno supports this many inputs. Or, is there any way to create a digital value like this that the Arduino can receive based on analog input (just high-low)?[/QUOTE] 14 digital + 6 analog inputs. [url]http://arduino.cc/en/Main/arduinoBoardUno[/url] See above though

Must... Resist... Must... Remain strong... [img]http://i.imgur.com/82K0dfN.jpg[/img] God dammit.

I got my little project to work! using a voltage reg + filter cap proved to do the trick. Without the filter cap the servo's go completely mental for some reason.

Is there anyone willing to help me a bit with electrical engineering? I have my high school physics still in the back of my head, but I must admit that I never got any further than calculating some basics things when it comes to electricity. I understand the basics but I really need someone to guide me a bit through my project. I have the following document, this is the circuit diagram I got from Martin (JEM), of the basic on/off remote. [t]http://i.imgur.com/JR8HWnJ.png[/t] [url=http://ecx.images-amazon.com/images/I/31qwrwNeTgL.jpg]The diagram for this piece of hardware[/url] [t]http://i.imgur.com/T3VFMEJ.png[/t] [url=http://www.musik-service.de/out/pictures/master/product/1/395764700_i00.jpg]The diagram for this piece of hardware[/url] I understand what resistors, diodes and Zener diodes are, but I don't completely understand why all these things are in the positions they are. To start: 1. What is the function of the Zener diode? I understand it allows current to flow in the reverse direction if the voltage is too low (right?), but why is it needed? 2. Why are there two diodes placed behind eachother? 3. Why is the resistor R2 there? Why can't it be removed? I want to use an Arduino to output a voltage, which should make the voltage on pin 4 range from 0V to 10V depending on what I output using the Arduino. Is it just as simple as placing an op amplifier where now the switch SW1 is, and how would I implement it? I'm kind of new to creating 'advanced' circuits like this so I'd love it if someone was able to guide me through it on Steam and explain me some things. I want to create the 2nd diagram, but a lot of it is unneccesary. I do not want the timer to be physical, so I don't even need half of the diagram. Though, I don't know what I can "cut out" to still make it work. I basically need the first diagram with just the adjustable voltage, which I can change by code. The timer and such will all be done by code. I want to order some parts, and I got almost all numbers, but I'd like it if someone could still check some things before I order it.

So I guess the DS1054Z became the new default beginner's scope?

Uh, I just replicated [url=http://i.imgur.com/JR8HWnJ.png]this[/url] but I left out D3 and D2. It seems to work, somewhat? [vid]http://webmup.com/nUd24/vid.webm[/vid] Uhm the size...

[QUOTE=Cyberuben;46692656] To start: 1. What is the function of the Zener diode? I understand it allows current to flow in the reverse direction if the voltage is too low (right?), but why is it needed? 2. Why are there two diodes placed behind eachother? 3. Why is the resistor R2 there? Why can't it be removed?[/QUOTE] 1. The zener diode allows current to flow in reverse once the zener breakdown voltage is reached, thus it clamps the voltage at the cathode to the breakdown voltage. 2. I'm taking a guess here and saying it's to prevent forward biasing of the base-collector junction. 3. A zener or transistor when fully turned on looks almost like a short, this is to limit the current, also zener diodes require a minimum current to work correctly

I'm still trying to find those nice $50 analog scopes that Dave Jones is often banging on about.

[QUOTE=Leestons;46693782]I'm still trying to find those nice $50 analog scopes that Dave Jones is often banging on about.[/QUOTE] You'd be lucky to get one for that price on ebay, unless it's broken, your best bet is to find your nearest electronics / radio club and see what they have.

I'm going to wait as I don't know what I'd do with a scope anyway, and would be better off putting my money into other things.

[QUOTE=Cakebatyr;46685428]Wish you told me about that... Not that I would have gone to Kelowna (no car), but I could have given you a list (photomultiplier tubes mostly).[/QUOTE] You can still inquire on their website. I won't be able to make it next year due to being committed to a Tokyo trip and pigging out on what remains of Akiba's electronics shops. Analog scopes can be found really cheap if you look places other than online. My tek 335 was $10 for example.

I had a christmas miracle! I had all my electronics in my bag, along with a tub of gel that I was [I]supposed[/I] to put in a bag and separate from my stuff. And the TSA didn't even look twice at me! I do still need a breadboard though, didn't have room for that. [editline]12th December 2014[/editline] And I couldn't bring my nice variable temp soldering iron either. Thats the biggest loss :(

[QUOTE=Leestons;46693782]I'm still trying to find those nice $50 analog scopes that Dave Jones is often banging on about.[/QUOTE] I have one you could have for £50 including P&P

P&P on an analog scope probably costs about the same as a DS1054Z.

[QUOTE=nikomo;46697126]P&P on an analog scope probably costs about the same as a DS1054Z.[/QUOTE] Since flagdog says they are both in the UK it shouldn't be that much. Shipping to America would be another story.

Anyone willing to help me get into electrical engineering via Steam / Skype?

No, but we'd probably all be willing to answer any questions you post here. [editline]12th December 2014[/editline] My to-do list for the upcoming Christmas vacation is getting a tad too big. I want to learn to use both EAGLE and KiCad, then work on my power supply idea, but then I also recently got the idea of doing an XY table thing, where the table is static, but there's a laser connected to two stepper motors, and you could burn or whatever, designs on objects. I saw a video on YouTube where a guy took some copper clad laminate FR4, used a laser to transfer his PCB design on it, and then etched it. Seemed kind of cool. But it got me thinking, you could maybe, just maybe, use a laser to burn a rudimentary silk screen to a board.

How come this circuit still works after leaving out D2 and D3? [t]http://i.imgur.com/JR8HWnJ.png[/t] And also a question from before: [quote]Is it just as simple as placing an LM358 where now the switch SW1 is, and how would I wire it? I'm kind of new to creating 'advanced' circuits like this so I'd love it if someone was able to guide me through it on Steam and explain me some things. I want to create the 2nd diagram, but a lot of it is unnecessary. I do not want the timer to be physical, so I don't even need half of the diagram. Though, I don't know what I can "cut out" to still make it work. I basically need the first diagram with just the adjustable voltage, which I can control using an Arduino. The timer and such will all be done by code too.[/quote] [t]http://i.imgur.com/T3VFMEJ.png[/t]