Using an Internal Mains transformer
A 50VA toroidal transformer powering an Oakley PSU2 designed to deliver up to 750mA per rail. Note
the wire loops fitted to the pads where normally the terminal block for the standby switch goes.
Be afraid, be very afraid...
Some of you old hands will laugh about the level of hysteria that surrounds direct mains
connection to DIY projects. However, this fear is more to do with our litigious society than
the real danger to the builder. Even so, I have had more than my fair share of high voltage
shocks over the years and it is not something I would want any builder to have to experience.
It has been purely luck that has saved me in several of those cases.
So I will say again – do not attempt to build a mains transformer into your modular case, or
any other project, without realising that to do so carries a risk of death to either you, or to the
person who may inadvertently put their fingers into your half built construction. Furthermore,
it is up to you as the builder of such an item to make sure, that once built, the item is safe to
use and meets all current safety legislation.
This is not a complete set of instructions on how to fit a transformer into a piece of
electronic equipment. This information is offered only as a guide and should not be
considered as your only source of information. No further information, other than that
included here, will be provided by me regarding the construction of mains powered
items.
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