| ??? 04/30/10 13:02 Read: times |
#175547 - Consider these points... Responding to: ???'s previous message |
Arun Kumar V said:
O.K People, As i have been saying since the beginning of this post, I already have a 3 year old successful design which uses a Trafo.
I am assuming, that a "Trafo" is a Transformer. Takes merely 3 seconds to type the whole word. Arun Kumar V said:
My client for whom i designed the product wants me to reduce the B.O.M cost and shipping cost which is directly connected to the Trafo ( Weight + cost). Nowadays, good quality small size line freq iron core trafo's have become a rare commodity and the trafo makers have nearly stopped taking oreders for these type of trafo's, instead they have huge demand for hi-freq ferrite core trafos which are used in SMPS designs. because of these hurdles my client wants me to change the design to replace bulky trafo with a smaller, lighter, cooler SMPS card. Accepted and agreed. You do the same thing, but with protection, can't you use an opto to isolate the Mains from the CPU? An opto will cost not more than Rs.4/-. Arun Kumar V said:
As for the safety of the enduser, My design does not use any inputs/keys, its an Ir remote Dimmer and the whole circuit is enclosed in a ABS plastic box. It is still a risk to you, your employers and technicians.... Arun Kumar V said:
My client has shown a competitor's product which uses capacitive resistance P.S and Direct Mains ZCD and the final product is as heavy as a pack of cigarettes. its been in the market since 4 years and asks me, why can't we do ours on similar lines ? Its totally your call. If anything goes wrong, the rope will be around your neck. Remember this and then proceed. Arun Kumar V said:
I feel writing off appnotes of several reputed companies as absurd is not right and many of us have derived reasonable amount of help from these very appnotes and nobody can deny this fact. Mostly, they are correct, does not mean that ALL of them are correct. You must refer to the complete document, especially the fine print and errata. Arun Kumar V said:
This topic has turned into a situation which is similar to where a parent finds it awkward to discuss about Sex education with his teenager and tries to avoid the discussion. Senior members do not want to divulge on this topic citing safety issues. Even I am having a teenager at home, so I am very much aware of this situation. As and when the situation comes, we DO discuss topics such as Sex Education. But believe me, on this forum, there is total transparency, No one is hiding any information, whereas, here topics are discussed very freely and openly. Arun Kumar V said:
How will one ever know the result unless he tries it, isn't that the spirit/essence that a designer should have ? Oh, so you want to Electricute someone, and then learn from it...Good. Arun Kumar V said:
I haven't worked with a Zilog Z8 and since i feel 8051/2 are its descendants, so their I/O pins structure might be similar. Mostly MCS51 have weak pullups and strong pull down. But you have to read the data sheets, because, this has changed over the years. Many manufacturers have strong pull up and strong pull down also, some are having High Voltage tolerance, (refer to Philips 89LPC87x series). Bye, Kiran V Sutar |
