RL3 and RL4 are both heating elements in slot 1 - likely just one heating element with a tap somewhere - that indeed acts like a voltage divider.
The power to the circuit flows from in between those heating elements, through a single rectifier (D1), through a 1W resister (R1), before being clamped to 5.1V by a zener (VZ1). The use of the heating element as a voltage divider is just to get closer to the target voltage (<15V considering the rating of C1), using the fact that a heating element is just a resistor with an enormous power rating. No one cares about the power efficiency of a toaster control circuit.
However, the schematic is missing a connection to VCC from the 5V rail it created - it only connects to the high side of the mains relay/toast magnet as well as the bagel button. It was supposed to connect to VCC, which in that schematic is only connected as to the clock circuit.
(I was not using the RL numbers when I numbered the heating elements in my previous comment originally - my bad. I updated the comment.)
The power to the circuit flows from in between those heating elements, through a single rectifier (D1), through a 1W resister (R1), before being clamped to 5.1V by a zener (VZ1). The use of the heating element as a voltage divider is just to get closer to the target voltage (<15V considering the rating of C1), using the fact that a heating element is just a resistor with an enormous power rating. No one cares about the power efficiency of a toaster control circuit.
However, the schematic is missing a connection to VCC from the 5V rail it created - it only connects to the high side of the mains relay/toast magnet as well as the bagel button. It was supposed to connect to VCC, which in that schematic is only connected as to the clock circuit.
(I was not using the RL numbers when I numbered the heating elements in my previous comment originally - my bad. I updated the comment.)