Program launch: "Get Paid to Publish your Project!"

[H3LIO]

I use a LM358 because it's a general purpose Am-pop, probably it's a common component most off us have. The typ SR of LM358 it's 0.6 V/

[Hero999]

At last, I also agree with the fact that peer review is important for a good design, but this advertisement asks us to submit the projects that we have already designed and built.

Yes I know and it also says it can't be published anywhere else on the Internet so it's not possible to get a peer review until it's published here.

Some of them may have some design issues because not all of them were designed by professionals. The three projects I submitted were lying somewhere at the corner of my room for a while. I thought, in this recession, if I can make some extra money by selling them here, then why not, I would buy few more components for my future projects. That was my motivation. And let me tell you one more thing, a good quality, error free, peer reviewed, and purposed to sell project would worth more than $80, and you know that.

Yes I agree.

I've attached the final version with all of my red pen removed.

I have one more suggestion: perhaps a more common transistor could be suggested if they are unable to find the S8050? I've added the BC338 which is pretty popular.

I'll make some changes, post them on the forum and if you or anyone else thinks I've made a mistake they can let me know. Once we've finalised the design, I'll email it to the webmaster and he can update it.

Hi, I

[H3LIO]

Thanks Hero999, I will try this weekend or next week and then I will let you know how it works.

I'm attaching the code some part of the code is comment because  I'm testing a few things. the code is in basic.






H

[Hero999]

Thanks for that.

I think all projects containing programmable devices published on this site should have source code; not much can be learnt from a hex file, except disassembly, which is not easy.

[bogdanfirst]

I intend to send a project for publishing, and I've got a couple of questions:

1. As the project will also be published on my personal site, it sometimes gets mentioned on other websites. I've had projects mentioned, for example, on the Electronics Lab blog, or other sites such as Hack a day. Is that acceptable, considering that I did not submit my project to the respective sites?

2. If the project is published on Electronics Lab and i get paid, does electronics lab have any rights upon my project, or does it remain my intellectual property?

3. When can I publish the project on the personal site? Is there any restriction such as that it has to be published after electronics- lab ?

[mixos]

1. Yes, it's acceptable.
2. After publication you have the rights on the project.. as the project is published with your name and email
3. No there is no restriction

[H3LIO]

Hi Hero999,

" found the datasheet for the MCU you're using and noticed that the I/O pins probably won't be abe to supply enough current to ensure a transistor driving a 300mA load will saturate properly so I used two transistors rather than one. Tr2  will deliver between 17mA and 21mA to T1's base but the impedance seen by the MCU's I/O pin will be about 10k so hardly any current will flow out of it."

I try but doesn't work because I need a transistor to be able to drive +/-400mA Load. but this weekend I will do the calculations to see if the values are matching. Using a mosfet driver will increase the price it will be twice more expensive then the LM358. It is useful if you need a faster switching time.

[Hero999]

Did you try it or is it what I've said about the fan drawing only 300mA put you off?

I deliberately overrated the design, it should still be fine, the BC338 is rated to 800mA and you're only using it for 400mA which is just half it's rating.

It's specified for an Hfe of at least 60 with a V_CE of 1V and a collector current of 300mA.

Assuming 400mA, a base current of 17mA, the forced beta will be 400/17 = 23.5 which is more than enough, even when the fact that the Hfe will be slightly lower at the higher collector current is taken into account.

The maximum power dissipation of the BC338 is 625mW, with a colllctor current of 400mA, V_CE = 1V, V_BE = 0.8V, I_B = 19mA the power dissipation will be around 415mW which is fine.

http://www.datasheetcatalog.org/datasheet/siemens/Q62702-C314-V2.pdf

Do you not have the BC338? Try the BC327 or BC548, which are high gain and rated to 500mA and 800mnA respectively.

It's not too critical but the transistor needs to have enough gain (>25) and low enough V_CE (preferably 1V or less) at 400mA. If the transistor gets too hot, it probably means V_CE is too high, causing it to dissipate too much power, try reducing R3 to get more base drive.

[bogdanfirst]

Are the projects listed under Submitted projects actually approved?

[mixos]

Are the projects listed under Submitted projects actually approved?

Yes, it means they are approved.

[bogdanfirst]

Thanks! I'm working on the documentation for mine, will send it soon.

[H3LIO]

Hi Hero999,

It works but only with a duty cycle higher than 70%, ib = 12mA. Tomorrow I'm going to change the resistors, let you know.

[Hero999]

Does the transistor get hot?

How did you measure Ib?

You need to use a 'scope with either a current probe or to measure the voltage across R3 and working out the current using Ohm's law. If you use a meter, you can only accurately measure it when the duty cycle is 100% because the  meter will only accurately measure DC or 50/60Hz AC.

Here's another idea using a PNP transistor to switch the positive side of the fan's power supply.

[H3LIO]

"How did you measure Ib?"

I didn