Conrad Digital Thermometer Module With LED Display Kit 192147 Data Sheet
Product codes
192147
2.5
A screened direct voltage of approx. 7 – 18 V= is applied to the solder pins
marked with “+” and “-”. It must be noted that the power supply unit used must
conform to VDE-regulations.
marked with “+” and “-”. It must be noted that the power supply unit used must
conform to VDE-regulations.
2.6
Depending upon the wiper setting the spindle-trimmer will be pointing to some
temperature.
temperature.
2.7
If the 7-segment displays do not glow as expected or if the equalisation
described below cannot be done or else any other function is not possible, then
immediately cut off the operating voltage and check the complete printed circuit
board once again according to the checklist given below.
described below cannot be done or else any other function is not possible, then
immediately cut off the operating voltage and check the complete printed circuit
board once again according to the checklist given below.
Checklist for fault search
Cross out each step!
Has the correct operating voltage been set?
Is the polarity of the operating voltage correct?
Are the 7-segment displays inserted correctly in the sockets? Decimal points must
point in the downward direction (in the direction of IC1).
Have the resistors been soldered correctly in terms of value? Check the values once
again in accordance with 1.1 of the construction guidelines.
Have the diodes been soldered with the correct polarity? Does the cathode ring
placed on the diode match with the imprint on the printed circuit board?
The cathode ring of D1 must point away from C2.
The cathode ring of D2 must point away from IC1.
The cathode ring of D3 must point to IC3/IC1.
The cathode ring of D1 must point away from C2.
The cathode ring of D2 must point away from IC1.
The cathode ring of D3 must point to IC3/IC1.
Have the electrolytic capacitors been polarised correctly? Compare the polarity
printed on the electrolytic capacitors “+” or “-” once again with the print on the circuit
board or in the component diagram in the construction manual. Note that depending
upon the make, “+” or “-” can be marked on the electrolytic capacitors!
board or in the component diagram in the construction manual. Note that depending
upon the make, “+” or “-” can be marked on the electrolytic capacitors!
Have the integrated circuits been inserted in the sockets with the correct polarity?
Notch or point of IC1 must point to R2.
Marking of IC2 must point to D2.
Marking of IC2 must point to D2.
Are all the IC-contact pins really inserted in the socket? It can happen very easily
that a contact pin gets bent or skids past the socket while inserting.
Is there a solder strap or a short-circuit present on the soldering side? Compare the
connections of the conducting paths, which possibly look like an unintended solder
strap, with the diagram (grid) of the printed circuit board and the circuit diagram in
the instructions, before you break a conductor (supposed solder strap)!
strap, with the diagram (grid) of the printed circuit board and the circuit diagram in
the instructions, before you break a conductor (supposed solder strap)!
To be able to easily ascertain the conductor paths or conductor breaks, hold the
soldered printed circuit board against light and look for these unwanted side-effects
from the soldering side.
from the soldering side.