Panasonic is part of a large worldwide groupselling relays and associated switching products under different brand names in different territories.The conditions of use in some territories may differ from those customary in Europe. In particular there are often major differences in regard to national and international specifications, such as UL, CSA, VDE, SEV, EVE, SEMKO, etc. Thus, when considering contact loads as stated in this catalogue (e.g. 10 A, 30 VDC for the SP relay) its hould be understood that these values are not necessarily an absolute maximum but tested ratings. Mostly the stated value has been tested for a certain life expectancy as stated by the manufacturer or the respective test house. Thus, under different conditions, the stated “maximum” may, in practice, be safely exceeded.
Inelectroniccircuits
wherethecircuitvoltagesarenotsohigh,
adiodecanbeusedwithareverse
breakdownvoltageofabout2to3times
thepowersupplyvoltage.Effectivewhen
connectedtobothcontactsifthepower
supplyvoltageis24or48Vandthe
voltageacrosstheloadis100to200V.5to1Qper1Vcontactvoltage
Valuesvarydependingontheproperties
oftheloadandvariationsinrelay
characteristics.
Diodeand
zenerdiode
circuit
NG Effectivewhenthereleasetimeinthe
diodecircuitistoolong.
*IfusedwithACvoltage,besurethe
impedanceoftheloadissufficiently
smallerthanthatoftheCRcircuit
Iftheloadisarelayorsolenoid,the
releasetimelengthens.
Diodecircuit NG
Thediodeconnectedinparallelcauses
theenergystoredinthecoiltoflowtothe
coilintheformofcurrentanddissipatesit
asjouleheatattheresistancecomponent
oftheinductiveload.
(G:Good,NG:NoGood,C:Conditional)
Circuit Application
AC Features/Others DevicesSelection
CRcircuit
Iftheloadisatimer,leakagecurrentflows
throughtheCRcircuitcausingfaulty
operation.
• Mounting the protective device
In irc it, to
lo tiv ,
re ito ris e
im ity t.5to1pFper1Acontactcurrent
r:0.Thiscircuitfurther
delaysthereleasetimecomparedtothe
CRcircuit.Capacitor“c”actsto
suppressthedischargethemomentthe
contactsopen.
Asaguideinselectingcandr,
c:0.
Useazenerdiodewithazenervoltage
aboutthesameasthepowersupply
voltage.
• Abnormal corrosion during high
frequency switching loads
(spark generation)
If, is
s itc fre -
g rro is
o fro tio ith itro n
a rc
d rin g
Contact
Althoughextremelyeffectiveinarcsuppression
asthecontactsopen,thecontactsare
susceptibletoweldingsincechargingcurrent
flowsto“C”whenthecontactsclose.Useacapacitor
“c”withabreakdownvoltageof200to
300V. tio irc its
a .
If ffe tiv s
o tiv s
a ith in
5 .
s itc ire in
c irc its a
h fre .
Contact
Althoughextremelyeffectiveinarcsuppression
asthecontactsopen,thecontactsare
susceptibletoweldingsinceenergyisstoredin
“C”whenthecontactsopenandshort-circuit
currentflowsfrom“C”whenthecontactsclose.
Contact
G
Contact
Contact
G
Contact
G
Contact
G G
• tio irc its n
in fig righ t.Thiscircuit
alsoslightlydelaysthereleasetime.Resistor“r”actstolimitthe
currentwhenthepoweristurnedonthe
nexttime.General Application Guidelines
a to
c firm tio .Testtoconfirm.(2to5timesthereleasetime
listedinthecatalog)
Useadiodewithareversebreakdown
voltageatleast10timesthecircuitvoltage
andaforwardcurrentatleastaslargeas
theloadcurrent.
A lth tiv lly
m iffic itc tiv e
lo tio irc it
w ill ris tic r
re tiv s.
Contact protection circuit tiv r
p tio irc its e
c te
th rre ill e
e ffe ct.
Varistorcircuit Varistor /
Usingthestablevoltagecharacteristicsof
thevaristor,thiscircuitprevents
excessivelyhighvoltagesfrombeing
appliedacrossthecontacts.UseACtypecapacitors(non
polarized)forACcircuits.
Effectivewhenconnectedtobothcontacts
ifthepowersupplyvoltageis24to48V
andthevoltageacrosstheloadis100to
200V.
622 ds_x61_en_relay_technical_information_091112D
