Building EVE
Power requirements
The EVE current draw at +/- 12V is 40mA max.. The
onboard 78L12 and 79L12 regulators allow EVE to be
powered directly from a maximum rail voltage of +/-
35V without the use of the rails bleeders R33 and R34
which can be ommitted using wire bridges. When
powering EVE from higher voltage rails use R33 and
R34 to bleed of the extra voltage. The shapes for R33
and 34 allow usage of 1 Watt resistors which with a
currentdraw of 40mA and a value of 680 ohms allow for
a maximum voltage drop of 25V resulting in a
maximum admissable rail voltage of +/- 60V.
Incase EVE is to be used as a standalone module please
provide for a symmetrical psu capable of delivering
+/- 15V @ 80mA minimum such as done by this kit:
https://www.tubeland.de/product_info.php?products_id=13
Choosing Components
EVE's primary goal is to offer a bare bone
proof of concept servo loop solution and has been designed with
cost effective readily available non-exotic parts in mind. The used 5532 opamps dates back to 1978 and by no
means represents the state of the art in opamp design. However since servo loops typically operate in the lf
domain it's specs are more then sufficient for the task at hand, refer to the 5532 datasheet for further
information.
Onboard Regulators
Contrary to EVE2018 the 2020 version uses the standard 78L12 and 79L12 regulators in a SOT89 package,
before ordering please verify the below indicated pin layouts are used.
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