CR= Crystal Rectifier (Diode) I've never actually seen it used before but found the answer google searching the hunch that the R might mean rectifier.
My First Pulse Width Modulator Mod
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Just cross referenced one of the markings "US1G" on digi key and the look like supper fast diodes.
Whoo Hooo, my digi key order is on it's way.... Lot's of eyeball burning SMD work coming my way.
Could mean anything really.
There's no hard and fast standard for silkscreen symbols. In the old days, when everything was hand soldered, silk screening was used to aid unskilled assemblers. The symbols were entirely up to the designer. These days, everything is done robotically so silkscreening is only to help the techs in setting up the machines, but they usually go by the engineering drawings rather than the boards themselves.
Cool i am interested to see how those boards work for you. What does it take like a day for your orders to get to you. Pretty sure digikey is in your state if i remember right.
I had to make another order today i always forget at least one thing. I went with mouser though. asked them to ship first class mail like craig pointed out in another thread. Not sure about your new list but the old one when i crossed it over to mouser you could have saved a couple bucks a board. Meant to say something earlier but it slipped my mind. Although i was looking at single part prices, since you bought 10 of each you get a nice price break so might not be quite that much per a board.
1 to 2 days. They are down in Minneapolis I believe. I should have the parts in the mail box Saturday evening.
Ok, be back this evening as I work on my tube mod for the proto i put together, I have to go bring the daughter school supply shopping.
So, I have been getting into microcontrollers a little over the past few days, ordered the TI msp430 launchpad kit (it's $4.30) and I might order an arduino nano to mess with as well. Turns out that with a little programming knowledge, you could easily surpass what the darwin does if you really wanted too.
If/when I do get to a microcontrolled mod, it will also be pwm so I will definitely let you guys know in this thread.
The reason for messing around with pmic stuff is just what bstedh mentioned a few posts ago about the different ohm carto's acting very differently with pwm. I noticed this too, and even though I only use dual coils now, not everyone does so it is something that will have to be considered in the future.
If/when I do get to a microcontrolled mod, it will also be pwm so I will definitely let you guys know in this thread.
The reason for messing around with pmic stuff is just what bstedh mentioned a few posts ago about the different ohm carto's acting very differently with pwm. I noticed this too, and even though I only use dual coils now, not everyone does so it is something that will have to be considered in the future.
You'll definitely have much more control over PWM with an MCU. The 555 is going to be pretty limited as far as control since it's analog which makes it more sensitive to design and environment. With an MCU, the duty cycle will be whatever you program it to. I think you'll be surprised how simple it will be with a micro-controller. They all have built-in PWM modules. PWM is a standard function for any MCU. They're designed for it.
I know Raidy on the forum here is using an ATTiny25 for a simple PWM controlled device. I've seen a schematic and program posted around here somewhere, but the program is in BASIC, yuck. That was actually the first programming language I learned when I was a kid. It's real easy to learn and use, but highly inflexible. Just an awful language for anything complex at all.
I was looking at the AVR parts. I'm starting a new mod design and was thinking of trying a different hardware platform, but don't know if I'm ready to take on the learning curve. Been using the PICs for quite a long time and I'm real comfortable with them.
Looked into the Arduino stuff a little bit. I thought it was a hardware platform, but it's actually a software/firmware platform with specific requirements for hardware compatibility. I wasn't aware of that. The assembly and C I've been using works fine for me so I don't really see the benefit personally, but I know Arduino has gained a lot of popularity in the last several years so there must be a reason. I'll have to look into it more when I get a chance.
I know Raidy on the forum here is using an ATTiny25 for a simple PWM controlled device. I've seen a schematic and program posted around here somewhere, but the program is in BASIC, yuck. That was actually the first programming language I learned when I was a kid. It's real easy to learn and use, but highly inflexible. Just an awful language for anything complex at all.
I was looking at the AVR parts. I'm starting a new mod design and was thinking of trying a different hardware platform, but don't know if I'm ready to take on the learning curve. Been using the PICs for quite a long time and I'm real comfortable with them.
Looked into the Arduino stuff a little bit. I thought it was a hardware platform, but it's actually a software/firmware platform with specific requirements for hardware compatibility. I wasn't aware of that. The assembly and C I've been using works fine for me so I don't really see the benefit personally, but I know Arduino has gained a lot of popularity in the last several years so there must be a reason. I'll have to look into it more when I get a chance.
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I was just about to order some Arduino boards to play around with also, but after looking at it I got the impression that the language has built in aliases for the ports so like you said, the hardware would have to be set up exactlly the same if you wanted to port a project. On top of that it only supports a couple of the AVR chips. Basically a more powerful Basic Stamp.
Check out the AVR Butterfly for a cheap way to look into AVRs. It uses the atmega169 chip and you just need to make up a simple serial cable to program. You won't have to learn a new language. I think they cost $20 for a board with a built in LCD, Piezo speaker, joystick etc. Two full ports are free, but only one of the adc channels is free. The flexibility in programming languages makes it more attractive to me.
I'm embarrassed to say that I still use a basic compiler. I'm an amatuer at this stuff so sometimes I will go many months without writing a single snippet. Basic makes it easy for me to pick up where I left off. The compiled code is usually much more bulky than the same thing written in assembly or C though.
The reason I went with the TI launchpad setup was not only price, but how easy it is to port. The chips have internal oscillators and require very few, if any, other components. Most videos I have seen people pull the chip and stick it straight in the breadboard to show off their project, I like that. New chips are $1-$2 and only twice the size of the 555, and thats if you are still into through hole DIP stuff. You can get other smaller packages too.
The real upside to Arduino is the community support. There are TONS of projects and ideas out there, as well as GUI drag-and-drop programming interfaces and stuff. Makes everything super easy to get a project going. Unfortunately, you have to spend more to get a setup where you can port the chip when you are done, and the chips are larger and require external oscillators and stuff. Although, arduino is supposed to have some android compatability somehow. That just opens all kinds of silly things up, super amoled 5.5" touch screen vaporizers that run angry birds anyone? I suppose anythings possible if you have the $$$.
Not that the 555 pwm stuff should be pushed to the side, I have been using mine for almost a month now and it is the best vaporizer I have ever used (as far as flavor and vapor are concerned).
The real upside to Arduino is the community support. There are TONS of projects and ideas out there, as well as GUI drag-and-drop programming interfaces and stuff. Makes everything super easy to get a project going. Unfortunately, you have to spend more to get a setup where you can port the chip when you are done, and the chips are larger and require external oscillators and stuff. Although, arduino is supposed to have some android compatability somehow. That just opens all kinds of silly things up, super amoled 5.5" touch screen vaporizers that run angry birds anyone? I suppose anythings possible if you have the $$$.
Not that the 555 pwm stuff should be pushed to the side, I have been using mine for almost a month now and it is the best vaporizer I have ever used (as far as flavor and vapor are concerned).
Has anybody found a good quality thumbwheel POT. The standard ones from Digikey seem like they will be OK but I don't know what the life expectancy will be on them. The will work fine for putting together these trial boards but I have been looking for one that will hold up better over time and have had no luck finding anything that is small and rugged.
Pretty much all the small trimmers have a mechanical operations of 200 cycles. Which is pretty bad. A 10 turn trimmer will only get you about 2000 rotations. Only thumbs that I have seen that are built to last are audio taper( Logarithmic) ones. One option is to look into IC trimmers. I think breakthru has made a mod with one.
My Mouser order didnt ship till today so it will be Monday or Tuesday before I etch my board. Looks like i will have room for two more of the PWM boards if you want to make some changes let me know.
EDIT:.........I guess it helps if you look , these here are rated @ 10,000 rotations . But they dont seem to stock them at Digikey no joy at Mouser either
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=1625938-2-ND
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I got my digi order in this afternoon. However, i had to go to a birthday party and they made me have a couple of Jack-N-Coke's. I'm not even going to atemt anything untill tomorrow.
Hehe, I understand that. I've tried to do this stuff when not fully sober before and regretted it. Though, one time in an electronics lab in college, there was a pop quiz and I had been having some beers with friends before I went to class. I almost blew off going to class, but figured being there a little buzzed would be better than not being there at all. I thought for sure there was no way I'd be able to do the test, so I just winged it with little concern. Turns out, my lack of attention actually helped me score well on the quiz. Surprised the hell out of me. Sometimes it's good not to think too much.
I was hoping to get going on these boards this afternoon but now it has to wait until this evening. Mowing, watering, and pulling the starter out of my expedition have taken priority.
I know how that goes always something coming up getting in the way of progress. Was going threw my order and these SMD switches i got are just too damn small so I have another order i need to place. I added that Ti lanchpad eval board to the cart. I figure for $4.30 what hell might as well give it a shot. Kinda wishing i would have majored in programming instead of networking when i went back to college.
Oh Yeah got the fets in the mail yesterday , Thanks. Might just have to play around on the breadboard here in a little bit.
I hear that, I switched majors three times in college. ME, CS, EE. Ended up graduating with EE, but there there are times I wish my programming skills were better. For as much as I use what I learned in college, I could have probably learned the EE stuff on my own. Still have a hard time with C sometimes. I use assembly a lot. As painstakingly tedious as it is, it's just so much easier for me to understand. One benefit though, it makes super tight code. No compiler putting lines and lines of canned routines in your machine code.
Ok, I got one board together. No idea if it works. My soldering was a bit messy. Need a better iron, my $5 cheapy just aint cutting it. I have to rig something usable up for batteries to test it out. I will work on that tomorrow. Too many finger burns and teary rosin eyes... Gotta get some shut eye for work in the A.M..
The POT wheel hits the legs of the 555 so If you make more boards you will want to back it off a little.
I drilled the power holes out a little too much. I had to surface solder the neg output because I lifted the solder pad.
I ordered too big of a 220K res for the LED so I had to turn it a little and scrape a new pad.
The POT wheel hits the legs of the 555 so If you make more boards you will want to back it off a little.
I drilled the power holes out a little too much. I had to surface solder the neg output because I lifted the solder pad.
I ordered too big of a 220K res for the LED so I had to turn it a little and scrape a new pad.
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Looks pretty good. If you have a hot plate you can warm the board up to around 180 degrees soldering will go a lot easier. But then you have to worry about burning yourself on the hot plate. But after a few times you tend to not touch it anymore. Let us now how it goes, going to be interesting to hear how well it works or in the worst case how much smoke it put off when you plugged it up to power 
Yes, that does look really nice. Good job there. Hope it works beautifully for you.
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