Yes, I see a problem , Lightning spikes and the full peak mains voltage when the mains is switched on at its voltage peak will pass straight through your capacitors causing a safety hazard and may destroy the insulation of the transformer if it is not rated for this voltage. Nick Rouse ----- Original Message ----- From: Pierre SELVA To: Forum Safety-emc Sent: Friday, January 11, 2002 5:18 PM Subject: TR: 60950 - Insulation between mains and secondary with capacitors
Hi forum members, I would like to know your meaning on the following : The concerned product is in the 60950 scope (EN, UL or IEC). I would like to make the insulation between the mains and the secondary without transformer, but only with capacitors (X rated). In fact, I need to use only the high frequency signals transmitted on the mains. In this case, the capacitors are considered as short circuit, and the 50 (or 60) Hz is cutted by caps. The circuit is as follow : C T1 ---------------| |-------------+ +----- Mains + + Secondary part ---------------| |-------------+ +------ C C are X rated capacitors T1 is only a signal transformer (not use for galvanic insulation) My questions are : - Is this insulation correct according to reinforced insulation requirements ? - May I use only one caps for C, or 2 serial caps (in case of first default) ? - Do you see other critical points regarding 950 requirements ? Thanks a lot for your contribution, Best regards, Pierre ======================================== eLABs (emc, safety and radio labs) Pierre SELVA 18 Rue Marceau Leyssieux 38400 SAINT MARTIN D'HERES - FRANCE Phone : 33 (0)6 76 63 02 58 Fax : 33 (0)6 61 37 87 48 e-mail : e.l...@wanadoo.fr ps.el...@laposte.net ======================================