An operation-time controller for a recording potentiometer

Publisher’s version / Version de l'éditeur:

Canadian Journal of Technology, 33, pp. 303-305, 1955

READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.

Questions? Contact the NRC Publications Archive team at

PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.

NRC Publications Archive

Archives des publications du CNRC

This publication could be one of several versions: author’s original, accepted manuscript or the publisher’s version. / La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur.

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at

An operation-time controller for a recording potentiometer

Handegord, G. O.; Cole, D. G.

https://publications-cnrc.canada.ca/fra/droits

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

NRC Publications Record / Notice d'Archives des publications de CNRC:

https://nrc-publications.canada.ca/eng/view/object/?id=dd21fdc4-a37d-43ff-b869-9264afce2f1b

https://publications-cnrc.canada.ca/fra/voir/objet/?id=dd21fdc4-a37d-43ff-b869-9264afce2f1b

aFF

8er

1TB}

N21t2

no. 2T

c . 2

SLDC

Reprinted from Conadian lournal of Teclwalogg' 38: 303-305' 1955

ANoPERATIoN-TIMEcoNTRoLLERFoRARECoRDINGPoTENTIoMETERI B v G . O . H . l N o B c o R D A N D D ' G ' C o r ' e A N A L Y Z E D

certain applications of recording potentiometers require that a record be made for oriy p"rt of each day. In some cases, such as solar radiation measure--"n,r, thi ,,;;" period of the recorder does not coincide with normal working hours and manual starting and stopping of the instrument is not possible' The instrument can be ope"rated coniinuously but this results in an excessive amount of chart being used, particularly in the winter months when sunshine occurs for onlY eight hours.

A standard time switch, such as the "lnter-matic" Model TS-60SP' manu-factured by the International Register Co', may be employed to stop and start the instrument at any predeteimined time. This time switch is commonly u s e d i n b u s i n e s s p l a c e s t o o p . , " t " d i s p l a y l i g h t i n g d u r i n g t h e d a r k h o u r s o f the evening.

W h e n t h e p o t e n t i o m e t e r u s e d i n c o r p o r a t e s a s t a n d a r d c e l l c i r c u i t w i t h automatic standardization, one difficulty arises in that the time switch may stop the instrument when the standardizing circuit is closed, resulting in an undesirable drain on tJre standard cell during the "off" period. This difficulty ,n.V U" overcome by incorporating a micro switch in parallel with the time .*ilr, to operate the instrument should the time switch open while standard-ization is in Progress.

T h e B r o w n r $ X I I V - X - 2 T , s t r i p c h a r t r e c o r d i n g p o t e n t i o m e t e r u s e d f o r solar radiation measurements in Saskatoon has been modified in the above manner. The time switch and micro switch are incorporated into the instru-ment as shown in Fig. l. The micro switch employed is a normally open type # B Z - } F \ , i n s t a l l e d s o " t h a t i t s c o n t a c t p i n b e a r s a g a i n s t t h e s t a n d a r d i z a t i o n " l i d e * i . " m e c h a n i s m . D u r i n g s t a n d a r d i z a t i o n , t h e m e c h a n i s m i s m o v e d i n towards the chassis so that th1 micro switch pin protrudes fu-lly, thus closing the switch and operating the instrument until standardization is complete' The micro switch is mounted on a brass plate which is secured to one of the mounting posts of the standardization assembly cover as shown in Fig. 2' Both the time switch and micro switch are wired in parallel with the drive s w i t c h a s s h o w n i n F i g . 3 ' T h i s w i r i n g a r r a n g e m e n t d o e s n o t i n v o l v e a n y c h a n g e in the oliginal wirinfof the instrument and all the connections may be made to the terminal board on the rear of the chassis'

. I h e t i m e s u - i t c h a n d m i c r o s w i t c h o p e r a t e o n l y t h e c h a r t d r i v e c i r c u i t o f the instrument, power being supplied continuously during both "on" and"off" p e r i o d s t o t h e a m p | i f i e r c i r c u i t a S r e c o m m e n d e d b y t h e m a n u f a c t u r e r . I n t e r . lri,*oa operation of the recorder as determined by the setting of the time

l l s s u e d as N.R.C. No.3631 ' 303

t e c h n l e a l P a P e r N o . 2 7

of thc

D l v ! - s l o n o f B u l l d l n g R e s e a r c h

N.R.C. No.863I

il

ilrur|l

_{urur|ilUlilll}

_ilt

ruultru

ilil

il

P n l c e 1 0 c c n t r

304 CANADIAN JOURNAL OF TECFINOLOGY. VOL. 33

Frc. l.

HANDEGORD AND COLE: POTENTIOMETER 305

switch is achieved

with the instrument chart drive switch in the "off" position.

Continuous operation of the recorder is readily obtained by moving the chart

drive switch to the "on" position.

@@@

oHART nto7oR ltr{t7cu

C'|AR,T MO7OR, VIR,IN6 DIA6R'AM

o#

o@@

TIIART MOTOR h/IR,IN6 OIA6R,AM

vtTH TTMER

4 MTCRO

ivtr

Fro. 3, Chart motor wiring diagram.

The total cost of materials required for this automatic switching arrange-ment is approximately thirteen dollars. The savings involved in chart con-sumption ior the particular application cited will be approximately eighteen dollars per year, based on an aveiage period of 14 hr. of sunshine and a chart cost of four dollars per roll.

RBcBrvBo Apnn 14, 1955' Pnarnre RBcrox.ll- StAtIoN, DrvrsroN or Buu.orNc Rrseencn, N.q,rror.IAL ResBencr Corri.rcrr., Sesreroox, CeNaPe,