Technology of Q 2500 colour TV set
If an error occurs - H level on pin 94 of the There may be applications, however, for
CCU - the CCU swtiches the device after 2 which the video recorder remote control is not
seconds to standby operation. available and the TV remote control emits
another code that the recorder does not un-
derstand. For this a video menu is provided in
4.1.10 AV operation chassis Q 2500, which is called up in the re-
mote control with ?V=?. This allows the basic
The circuit is designed so that AV operation functions of the recorder to be used. If for
with switching voltage on programme loca-?Connect video devices? three devices are
tions can be programmed. selected, they can all be controlled independ-
ently of each other.
Setting is implemented in the menu under
connect AV device. In this operating mode the RSIG signal pre-
The menu makes clear the exact procedure sent on pin 5 of the CCU is controlled inter-
for setting up or you can refer to the overview nally via a code converter and then output via
in the operating instructions. Monitoring of the pin 97 of SDA 6000, which is now low resis-
switching voltage on pin 8 of the AV socket is tant. The other signal path is identical with the
implemented via transistors Q 2737/Q 2726 first possibility.
and Q 2746 for AV1/AV2 and AV3. The three
emitter followers are connected respectively The code converter changes the RC 5 data
via voltage dividers to pins 125/124 and 127 words of level 0, as they are delivered to the
of the CCU. IR receiver, to those of level 5, with which the
video recorder operates. Secondly, the code
In accordance with the Euro/AV standard, pin converter changes the RC 5 command into
8 of the AV socket is defined as 6V (16:9 op-the corresponding data word of the NEC code.
eration) and 12 V (4:3 operation) AV opera-Thirdly, the RC 5 commands are converted
tion. into the Korythso code.
The CCU monitors these voltages on its AV The three data words, both RC 5 of level 5, as
pins. By division of the respective voltages 6V well as the NEC code word and the Korythso
= 1.3V and 12V = 2.6V on the pins of the code word, are emitted serially by SDA 6000
CCU. If a switching voltage is detected by the pin 97. This means that remote control of re-
CCU, this switches over to AV operation on corders that operate with RC 5, NEC or
corresponding menu selection. Korythso code is possible.
Of course, a recorder must be used that can
process the remote control signal coming from
the AV switching voltage line. For this most
" IR signals
Loewe recorders have a converter.
For the remote operation of VTR devices via
the TV-IR receiver the RSIG signal is applied During output of the converted IR commands
transistor Q 2823 is blocked with L level on
to the Euro sockets pin 8.
pin 9 of the CCU. This prevents these signals
For this two signal paths are provided. In nor-being affected by IR signals from the receiver
mal and standby operation SDA 6000 pin 9 at on the operating component.
H level switches transistor Q 2823, and pin
97, which is also on the signal path, is made In order to achieve separate operation of the
high-resistant from SDA 6000, to avoid inter-three devices connected to the two Euro
ference. Via Q 2823 and I 2716 the RSIG sig-sockets, the circuit also contains RSIG signal
switching controlled by the CCU.
nal is passed on to the transistors for socket
selection. Use of the recorder remote control
is necessary for this.
Document Q 2500 69 ? Loewe ProCollege |
ACEC
