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I have ordered some samples from the MAXIM. Unfortunately the samples seems never arrive even though after 3 weeks time( I'm staying in Malaysia).

Then I go back to the notifications mail which stated that I reply to that particular message if got any enquiries. However when I replied, the mail administrator rejected the mail and say that the emaill address in not exist! The email address is: Alice_Loh@maximhq.com

Even after weeks of ordering, MAXIM still haven't send me any single chip!

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As I am in Hong Kong, I think most of the IC manufacturers will forward the sample order to the distributors in Hong Kong......... and I do think most of them are not willing to send samples especially we are for our own usage.... :-\

I haven't give an order yet.....hmm....... may be I should try Microchip first....... ;)

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I have ordered some samples from Allegro Microsystem on 27/07/2004. They reverted instanly that they forwarded the orders for approval. Waited 1 week no sign of getting anything.

Forward the email I received and ask about the status of the order. Reverted with the status "ship to customer". Cool... Waited patienly. 1 week passed, 2 week passed. I contacted the person incharge. No news, no reply... I lost my patience.

I send them an harsh email. Ask them to remove "sample order" links from thier website because it is cheating.

Guest what... immediately they called me and ask my FEDex number. Hmmm... Sometimes harsh emails might do the job...

I received thier parts on 17/08/2004. Suggest those who never received any ordered samples... follow my way. It might work.

Texas Instruments still the top of the list. Shipment in 5 working days. From US to Malaysia.

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I have ordered sample for hall effect IC's from Allegro Microsystem. There are 6 types all together. So far I have tried 3 different types. Guess what... non of them are working.

The function of Hall Effect IC is like reed switch. Turn on when in presence of magnet. But these IC's not doing the job. Wasted 4 hours of testing. Right no moving to opto interupter switches.

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I tried your suggestion. Three IC's never draw any current from the output pin when I moved the magnet nearer to IC while the circuit powered.

I replaced with another new Hall Effect IC. Measured and got voltage around 1 - 2V. So the IC works. Probably the IC damaged previously.

Anyway I have switched to simpler method by using reed switch with 555 timer IC.

I'm using 555 timer IC in order to control trigger width and pulse width. I have enclosed the circuit diagram.

I still encounter some problem. The circuit is stabe if I connect LED at output of second 555 timer IC. If I connect the output from second 55 timer IC output direct to 2N3055 base, both 555 timer IC get hotter and the result goes crazy (unstable).

Maybe today I will try method below :

reed switch -> 555 timer -> LM358 -> 2SC1061 -> 2N3055
Power Source : 12VDC

Hope this works. Your comments highly appreciated.


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You say the 555 get hot, I must ask (with the risk of being rude): is the 2N3055 correctly connected? I think maybe you need a resistor at the base, how is the load connected? The 555 can at 12V with output high sink lots of current trough the emitter diode and load (if any) to ground. This can be the reason for the heat.

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Thanks for the advice Ante, will try out soon. FYI, yesterday I tried with the setup below :

reed switch -> 555 timer -> LM358 -> 2N3055

These setup is using single 555 timer. The ICs never get hot and runs stable. Manage to control pulse width but unable to get trigger width. When ever I use two 555 timer as in the diagram, the second 555 timer IC gets hot and unable to get the expected result even I reassemble the whole circuit again.

OK, may be you were wondering what project I'm doing currently. I'm doing R&D on pulse DC motor. According to the internet source, these type of motor if tuned and setup correctly will become Overunity(OU). It means free energy. You get excess of output compare to input source. Skeptic? So was I initially.

I have been studying these stuff for a long time. Manage to see positive result few months back by just using basic method (reed switch -> transistor) but cannot confirm. Saw some voltage of the baterry increase while the motor was running. This is enough for me to continue research.

In order to enhance the setup I got to use a bit advance electronic parts. Since I'm new to electronic, I do a lot of trial an error :'(.

Maybe those interested can join to do this exciting/fun project. Some of the related links listed below :

1) http://www.geocities.com/theadamsmotor/
2) http://theverylastpageoftheinternet.com/menu/pulse_motors.htm
3) http://theverylastpageoftheinternet.com/menu/muller.htm

My project right now is the (1).

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Is it some kind of commutation for a motor like in a brush less fanmotor for instance?

Yes, you are right. When rotor magnet approaches Hall Effect IC, it sends signal to transistor to induce current for stator. Now stator become electromagnet to push the magnets away (repulsion). Basic concept.

reed switch -> 555 timer -> LM358 -> 2N3055 (works)

For this type of motors, precission and pulse width are very critical and important. Reed switch and hall effect ic will not produce the result if magnets on rotor arranged nearer.

I find opto switch is the best for this purpose. I need precission. Pulse width can be controlled by 555 timer. I have tested this method yesterday and it works. Today & tomorrow I will try to fix into my project motor. Will inform you the outcome.

Sceptic, yes absolutely. Basic rules: You can

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kumaran, It has been 5 posts since this thread was about sample chips. I am surprised the moderator of this section has let it go. Yes, please post the conversation about your project in it's own place. I keep getting notices about new conversations to this thread and they are not about sample chips.


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Hi everybody,
I used to get samples from maxim, but now they don't send me anything. I receive an email from Alice_Loh@ maximhq.com when I make a request, and I know I will receive nothing. >:(
Can you still request samples from maxim?
By the way, I can't go to the page with www.geocities.com/???, can anyone tell me why, and how to access.
Thanks. :)

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anananh, I think you have to be a business or organization to get a Fed Ex account. Likewise with the sample chips. You have to register as an engineer or business to get them from Maxim. How did you register? Many companies will never send sample chips to students or individuals.


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  • 2 weeks later...

anananh, i got the same problem as you before. Then i mail to the info@ maxim-ic.com to check for my sample request. After a few days, Alice replied, informing me that the samples have been shipped. Then, after another the 2 weeks, the samples finally arrived! (Late... better than never ;) ).

Maybe it's because we are registered under the title of "student", that's why they are not interest in ship us any samples.

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  • 3 weeks later...

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