Grounding of Shields
Question: We
have designed a battery powered handheld amplifier circuit. To shield
the amplifier circuit, we have covered the amplifier box with aluminum
foil. The shield is connected to the amplifier circuit common at a
single point. In all the shielding topic discussions that I have read,
it is emphasised to ground the shield. Since the equipment is portable,
how can it be grounded? Will the shielding be effective without the
ground connection?
Answer: A shield does not have to be grounded or have its potential controlled in any way to act as an effective shield. Many shields
are grounded for other reasons, such as electrical safety.