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


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Get Paid to Publish your Project!

We are proud to announce the "Get Paid to Publish your Project" program here at Electronics-Lab.com. Every project published under project section will get an instant PayPal payment of 80$ USD.



Get ready to submit your project at Electronics-Lab. To participate send your project to webmaster @ electronics-lab.com with "Get Paid to Publish your Project" in subject line and your project as attachment. Common file types (.doc, .jpg, .pdf etc) are accepted. After reviewing your project and approved for publication it will be published under project section and you receive the payment to your PayPal account. So simple!

A project to be valid should be:
- A high quality project.
- Designed by you.
- Not published elsewhere on the web.
- Has clear schematics, photos, description and PCB.

Every project approved will be published and will receive the payment. You will notified by email if your project is accepted.

If you have any questions, don't hesitate to contact us

Check submitted projects here

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To Hero999's point, the first project (Temp data logger)...

It says:

1. GP0 (Pin 7, I/P): This pin will be used to read the temperature value from DS1820 sensor


Pin 7 in the schematic is hard wired to +5V... how is that going to work?? Or is it just to early in the morning and I need more coffee?
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I agree, it seems like no one is checking the projects, a capacitor is also connected upside down, you don't have to be an expert to see that.

There again, what do you expect when you're only paying someone $80 to design a project for you? You can't expect people to sell their best designs at that price.

If you think I'm being harsh, there's a thread about it on another forum I visit.
http://www.eevblog.com/forum/index.php?topic=1153.0

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  • 2 weeks later...

What is the deal with not publishing elsewhere? Say I wanted to put it on my personal web site at a later date... How long are we talking? Forever? A couple of months?

I would like to submit some projects but ultimately they will all end up on my personal site. I don't mind delaying them and they meet the criteria.

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It is a "gentleman's agreement" that you will not publish your project elesewhere.
It will be too expensive to sue you if you break the agreement but you will probably be banned from here.

I submitted a few projects here when there was a contest. I did not win but it doesn't matter because I am happy that my projects were useful for other people.

Other websites copy projects. Some of the copied projects do not work.

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I am seeing few people commenting on the polarity of two capacitors that are used in two of my projects posted here, namely Learning board for PIC12F683 and Single chip temperature logger.  Both are 10uF, 50V capacitors and are used in TTL to RS232 Level shifting sections of my projects. It seems like they are connected upside down, but that's not true.

In order to translate TTL logic '1' (which is 5V) to RS232 logic '1' (which is -3 to -12V), I need negative voltage supply. Since I don't have one on my board, I am stealing it from the TX pin of PC RS232 port. At idle condition (when PC is not transmitting), the TX pin is at logic '1', i.e., at -3 to -12V. I am taking that negative voltage and feeding it back to its RX pin through a 4.7K resistor. So the +ive terminal of the capacitor is grounded, and the -ive terminal is connected to negative voltage supply, which is a proper way to connect a capacitor.

The pictures attached here describe how this works exactly.
Picture+2.png

Picture+3.png
And, when the PC is transmitting, the reverse biased diode connected between the TX and -ive terminal of the capacitance protect  it from charging in opposite direction. I didn't mention all these details in the project because I thought it would be too much to put on a hobbyist corner. I hope this answered why the capacitance is connected the way it is.

Thanks.
Raj

post-54616-1427914420578_thumb.png

post-54616-14279144206016_thumb.png

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You're right, thanks for signing up and offering an explanation.

I didn't understand how it worked but now you've explained it properly I get it.

I'm glad to see that the web master has changed it back.

I'm sorry about making the mistake but it actually further proves my point: if a design is not subject to a proper peer review, then it can easily contain errors. Just having one or two people review the circuit before it gets published is not good enough. We need to discuss new designs first, as we're doing here so we can iron out any errors before they are published.

There were some other changes I made to the schematic which I feel would make it work more reliably which have now been put reverted. I'll repost them and if you agree, I'll ask the web master to change it.

1) There should be no need for a resistor in series with the piezo buzzer, it's a high impedance device so there shouldn't be any need to limit the current. Was it just to loud and you needed to reduce the volume? If so I think you could offer an explanation,

2) Is it a piezo buzzer with a built in oscillator or just a piezo speaker which needs a squarewave to work?

3) It will probably work with 4k7 but the transistor will run cooler with a 470R base resistor because the saturation voltage will be lower.

4) Again, it might work without a 100nF capcitor in parallel with the PIC but it's always good design practise to include one.,

5) The minimum operating voltage for the LM7805 is 7V, below that it will fail to regulate and the output will fall, so that should be 7V to 12V not 6V to 12V. Source: datasheet http://www.fairchildsemi.com/ds/LM/LM7805.pdf

I have another question about the other project you've posted.
http://www.electronics-lab.com/projects/test/012/index.html

The circuit is powered from three 1.5V batteries so shouldn't the power supply voltage be 4.5V, not 5V?

Have you also checked that the temperature sensor gives accurate enough readings as the battery voltage drops?

The data sheet specifies an accuracy of 0.5

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Hero999,
I am sorry I was quite busy in past couple of days, so could not respond you. I liked the changes you made in the PIC12F683 board circuit. The piezo that I used requires square waves to create sound and the series resistor is unnecessary. The decoupling capacitor is a good practice, I forgot that. The input to LM7805 should be 7-12V, that was my mistake. You are welcome to post the revised version of the circuit and I appreciate for doing this.

About my data logger project, I am going to test few things with it this weekend and will ask the administrator to update on website, if required.

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. 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.

Thanks,
Raj

(I hope you didn't mind calling you Hero999 as that's the only name I know of you)

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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

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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 ?

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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.

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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 VCE 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, VCE = 1V, VBE = 0.8V, IB = 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 VCE (preferably 1V or less) at 400mA. If the transistor gets too hot, it probably means VCE is too high, causing it to dissipate too much power, try reducing R3 to get more base drive.

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